CIS Amazon Web Services Foundations Benchmark v5.0.0

Level 1

1 Identity and Access Management

Ensure contact email and telephone details for AWS accounts are current and map to more than one individual in your organization. An AWS account supports a number of contact details, and AWS will use these to contact the account owner if activity judged to be in breach of the Acceptable Use Policy or indicative of a likely security compromise is observed by the AWS Abuse team. Contact details should not be for a single individual, as circumstances may arise where that individual is unavailable. Email contact details should point to a mail alias which forwards email to multiple individuals within the organization; where feasible, phone contact details should point to a PABX hunt group or other call-forwarding system.

This activity can only be performed via the AWS Console, with a user who has permission to read and write Billing information (aws-portal:*Billing). 1. Sign in to the AWS Management Console and open the Billing and Cost Management console at https://console.aws.amazon.com/billing/home#/. 2. On the navigation bar, choose your account name, and then choose Account. 3. On the Account Settings page, review and verify the current details. 4. Under Contact Information, review and verify the current details.

Manual

If an AWS account is observed to be behaving in a prohibited or suspicious manner, AWS will attempt to contact the account owner by email and phone using the contact details listed. If this is unsuccessful and the account behavior needs urgent mitigation, proactive measures may be taken, including throttling of traffic between the account exhibiting suspicious behavior and the AWS API endpoints and the Internet. This will result in impaired service to and from the account in question, so it is in both the customers' and AWS's best interests that prompt contact can be established. This is best achieved by setting AWS account contact details to point to resources which have multiple individuals as recipients, such as email aliases and PABX hunt groups.

This activity can only be performed via the AWS Console, with a user who has permission to read and write Billing information (aws-portal:*Billing). 1. Sign in to the AWS Management Console and open the Billing and Cost Management console at https://console.aws.amazon.com/billing/home#/. 2. On the navigation bar, choose your account name, and then choose Account. 3. On the Account Settings page, next to Account Settings, choose Edit. 4. Next to the field that you need to update, choose Edit. 5. After you have entered your changes, choose Save changes. 6. After you have made your changes, choose Done. 7. To edit your contact information, under Contact Information, choose Edit. 8. For the fields that you want to change, type your updated information, and then choose Update.

Level 1

1 Identity and Access Management

AWS provides customers with the option of specifying the contact information for account's security team. It is recommended that this information be provided.

Perform the following to determine if security contact information is present: From Console: 1. Click on your account name at the top right corner of the console 2. From the drop-down menu Click My Account 3. Scroll down to the Alternate Contacts section 4. Ensure contact information is specified in the Security section From Command Line: 1. Run the following command: aws account get-alternate-contact --alternate-contact-type SECURITY 2. Ensure proper contact information is specified for the Security contact.

Manual

Specifying security-specific contact information will help ensure that security advisories sent by AWS reach the team in your organization that is best equipped to respond to them.

Perform the following to establish security contact information: From Console: 1. Click on your account name at the top right corner of the console. 2. From the drop-down menu Click My Account 3. Scroll down to the Alternate Contacts section 4. Enter contact information in the Security section From Command Line: Run the following command with the following input parameters: --email-address, --name, and --phone-number. aws account put-alternate-contact --alternate-contact-type SECURITY Note: Consider specifying an internal email distribution list to ensure emails are regularly monitored by more than one individual.

Level 1

1 Identity and Access Management

The 'root' user account is the most privileged user in an AWS account. AWS Access Keys provide programmatic access to a given AWS account. It is recommended that all access keys associated with the 'root' user account be deleted.

Perform the following to determine if the 'root' user account has access keys: From Console: 1. Login to the AWS Management Console. 2. Click Services. 3. Click IAM. 4. Click on Credential Report. 5. This will download a .csv file which contains credential usage for all IAM users within an AWS Account - open this file. 6. For the <root_account> user, ensure the access_key_1_active and access_key_2_active fields are set to FALSE. From Command Line: Run the following command: aws iam get-account-summary | grep AccountAccessKeysPresent If no 'root' access keys exist the output will show AccountAccessKeysPresent: 0,. If the output shows a 1, then 'root' keys exist and should be deleted.

Automated

Deleting access keys associated with the 'root' user account limits vectors by which the account can be compromised. Additionally, deleting the 'root' access keys encourages the creation and use of role based accounts that are least privileged.

Perform the following to delete active 'root' user access keys. From Console: 1. Sign in to the AWS Management Console as 'root' and open the IAM console at https://console.aws.amazon.com/iam/. 2. Click on <root_account> at the top right and select My Security Credentials from the drop down list. 3. On the pop out screen Click on Continue to Security Credentials. 4. Click on Access Keys (Access Key ID and Secret Access Key). 5. If there are active keys, under Status, click Delete (Note: Deleted keys cannot be recovered). Note: While a key can be made inactive, this inactive key will still show up in the CLI command from the audit procedure, and may lead to the root user being falsely flagged as being non-compliant.

• IAM User account root for us-gov cloud regions is not enabled by default. However, on request to AWS support enables 'root' access only through access-keys (CLI, API methods) for us-gov cloud region. - Implement regular checks and alerts for any creation of new root access keys to promptly address any unauthorized or accidental creation.

Level 1

1 Identity and Access Management

The 'root' user account is the most privileged user in an AWS account. Multi-factor Authentication (MFA) adds an extra layer of protection on top of a username and password. With MFA enabled, when a user signs in to an AWS website, they will be prompted for their username and password as well as for an authentication code from their AWS MFA device. Note: When virtual MFA is used for 'root' accounts, it is recommended that the device used is NOT a personal device, but rather a dedicated mobile device (tablet or phone) that is kept charged and secured, independent of any individual personal devices (non-personal virtual MFA). This lessens the risks of losing access to the MFA due to device loss, device trade-in, or if the individual owning the device is no longer employed at the company. Where an AWS Organization is using centralized root access, root credentials can be removed from member accounts. In that case it is neither possible nor necessary to configure root MFA in the member account.

Perform the following to determine if the 'root' user account is enabled and has MFA setup: From Console: 1. Login to the AWS Management Console 2. Click Services 3. Click IAM 4. Click on Credential Report 5. This will download a .csv file which contains credential usage for all IAM users within an AWS Account - open this file 6. For the <root_account> user, ensure the mfa_active field is set to TRUE or the password_enabled field is set to FALSE From Command Line: 1. Run the following command: aws iam get-account-summary | grep AccountMFAEnabled aws iam get-account-summary | grep AccountPasswordPresent 2. Ensure the AccountMFAEnabled property is set to 1 or the AccountPasswordPresent property is set to 0

Automated

Enabling MFA provides increased security for console access as it requires the authenticating principal to possess a device that emits a time-sensitive key and have knowledge of a credential.

Note: To manage MFA devices for the 'root' AWS account, you must use your 'root' account credentials to sign in to AWS. You cannot manage MFA devices for the 'root' account using other credentials. Perform the following to establish MFA for the 'root' user account: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. Choose Dashboard , and under Security Status , expand Activate MFA on your root account. 3. Choose Activate MFA 4. In the wizard, choose A virtual MFA device and then choose Next Step . 5. IAM generates and displays configuration information for the virtual MFA device, including a QR code graphic. The graphic is a representation of the 'secret configuration key' that is available for manual entry on devices that do not support QR codes. 6. Open your virtual MFA application. (For a list of apps that you can use for hosting virtual MFA devices, see Virtual MFA Applications.) If the virtual MFA application supports multiple accounts (multiple virtual MFA devices), choose the option to create a new account (a new virtual MFA device). 7. Determine whether the MFA app supports QR codes, and then do one of the following: - Use the app to scan the QR code. For example, you might choose the camera icon or choose an option similar to Scan code, and then use the device's camera to scan the code. - In the Manage MFA Device wizard, choose Show secret key for manual configuration, and then type the secret configuration key into your MFA application. When you are finished, the virtual MFA device starts generating one-time passwords. In the Manage MFA Device wizard, in the Authentication Code 1 box, type the one-time password that currently appears in the virtual MFA device. Wait up to 30 seconds for the device to generate a new one-time password. Then type the second one-time password into the Authentication Code 2 box. Choose Assign Virtual MFA.

IAM User account root for us-gov cloud regions does not have console access. This recommendation is not applicable for us-gov cloud regions.

Level 2

1 Identity and Access Management

The 'root' user account is the most privileged user in an AWS account. MFA adds an extra layer of protection on top of a user name and password. With MFA enabled, when a user signs in to an AWS website, they will be prompted for their user name and password as well as for an authentication code from their AWS MFA device. For Level 2, it is recommended that the 'root' user account be protected with a hardware MFA. Where an AWS Organization is using centralized root access, root credentials can be removed from member accounts. In that case it is neither possible nor necessary to configure root MFA in the member account.

Perform the following to determine if the 'root' user account has a hardware MFA setup: 1. Run the following command to determine if the 'root' account has MFA setup: aws iam get-account-summary | grep AccountMFAEnabled aws iam get-account-summary | grep AccountPasswordPresent The AccountMFAEnabled property is set to 1 will ensure that the 'root' user account has MFA (Virtual or Hardware) Enabled. AccountPasswordPresent set to 0 indicates that the root console credential has been removed. If AccountMFAEnabled property is set to 0 and AccountPasswordPresent is set to 1 the account is not compliant with this recommendation. 2. If AccountMFAEnabled property is set to 1, determine 'root' account has Hardware MFA enabled. Run the following command to list all virtual MFA devices: aws iam list-virtual-mfa-devices If the output contains one MFA with the following Serial Number, it means the MFA is virtual, not hardware and the account is not compliant with this recommendation: SerialNumber: arn:aws:iam::_<aws_account_number>_:mfa/root-account-mfa-device

Manual

A hardware MFA has a smaller attack surface than a virtual MFA. For example, a hardware MFA does not suffer the attack surface introduced by the mobile smartphone on which a virtual MFA resides. Note: Using hardware MFA for numerous AWS accounts may create a logistical device management issue. If this is the case, consider implementing this Level 2 recommendation selectively for the highest security AWS accounts, while applying the Level 1 recommendation to the remaining accounts.

Note: To manage MFA devices for the AWS 'root' user account, you must use your 'root' account credentials to sign in to AWS. You cannot manage MFA devices for the 'root' account using other credentials. Perform the following to establish a hardware MFA for the 'root' user account: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. Choose Dashboard, and under Security Status, expand Activate MFA on your root account. 3. Choose Activate MFA. 4. In the wizard, choose A hardware MFA device and then choose Next Step. 5. In the Serial Number box, enter the serial number that is found on the back of the MFA device. 6. In the Authentication Code 1 box, enter the six-digit number displayed by the MFA device. You might need to press the button on the front of the device to display the number. 7. Wait 30 seconds while the device refreshes the code, and then enter the next six-digit number into the Authentication Code 2 box. You might need to press the button on the front of the device again to display the second number. 8. Choose Next Step. The MFA device is now associated with the AWS account. The next time you use your AWS account credentials to sign in, you must type a code from the hardware MFA device. Remediation for this recommendation is not available through AWS CLI.

IAM User account 'root' for us-gov cloud regions does not have console access. This control is not applicable for us-gov cloud regions.

Level 1

1 Identity and Access Management

With the creation of an AWS account, a 'root user' is created that cannot be disabled or deleted. That user has unrestricted access to and control over all resources in the AWS account. It is highly recommended that the use of this account be avoided for everyday tasks.

From Console: 1. Login to the AWS Management Console at https://console.aws.amazon.com/iam/. 2. In the left pane, click Credential Report. 3. Click on Download Report. 4. Open or Save the file locally. 5. Locate the <root account> under the user column. 6. Review password_last_used, access_key_1_last_used_date, access_key_2_last_used_date to determine when the 'root user' was last used. From Command Line: Run the following CLI commands to provide a credential report for determining the last time the 'root user' was used: aws iam generate-credential-report aws iam get-credential-report --query 'Content' --output text | base64 -d | cut -d, -f1,5,11,16 | grep -B1 '<root_account>' Review password_last_used, access_key_1_last_used_date, access_key_2_last_used_date to determine when the root user was last used. Note: There are a few conditions under which the use of the 'root' user account is required. Please see the reference links for all of the tasks that require use of the 'root' user.

Manual

The 'root user' has unrestricted access to and control over all account resources. Use of it is inconsistent with the principles of least privilege and separation of duties, and can lead to unnecessary harm due to error or account compromise.

If you find that the 'root' user account is being used for daily activities, including administrative tasks that do not require the 'root' user: 1. Change the 'root' user password. 2. Deactivate or delete any access keys associated with the 'root' user. Remember, anyone who has 'root' user credentials for your AWS account has unrestricted access to and control of all the resources in your account, including billing information.

The 'root' user for us-gov cloud regions is not enabled by default. However, on request to AWS support, they can enable the 'root' user and grant access only through access-keys (CLI, API methods) for us-gov cloud region. If the 'root' user for us-gov cloud regions is enabled, this recommendation is applicable. Monitoring usage of the 'root' user can be accomplished by implementing recommendation 3.3 Ensure a log metric filter and alarm exist for usage of the 'root' user.

Level 1

1 Identity and Access Management

Password policies are, in part, used to enforce password complexity requirements. IAM password policies can be used to ensure passwords are at least a given length. It is recommended that the password policy require a minimum password length 14.

Perform the following to ensure the password policy is configured as prescribed: From Console: 1. Login to AWS Console (with appropriate permissions to View Identity Access Management Account Settings) 2. Go to IAM Service on the AWS Console 3. Click on Account Settings on the Left Pane 4. Ensure Minimum password length is set to 14 or greater. From Command Line: aws iam get-account-password-policy Ensure the output of the above command includes MinimumPasswordLength: 14 (or higher)

Enforcing a minimum password length of 14 characters enhances security by making passwords more resistant to brute force attacks. However, it may require users to create longer and potentially more complex passwords, which could impact user convenience.

Automated

Setting a password complexity policy increases account resiliency against brute force login attempts.

Perform the following to set the password policy as prescribed: From Console: 1. Login to AWS Console (with appropriate permissions to View Identity Access Management Account Settings) 2. Go to IAM Service on the AWS Console 3. Click on Account Settings on the Left Pane 4. Set Minimum password length to 14 or greater. 5. Click Apply password policy From Command Line: aws iam update-account-password-policy --minimum-password-length 14 Note: All commands starting with aws iam update-account-password-policy can be combined into a single command.

Ensure the password policy also includes requirements for password complexity, such as the inclusion of uppercase letters, lowercase letters, numbers, and special characters: aws iam update-account-password-policy --require-uppercase-characters --require-lowercase-characters --require-numbers --require-symbols

Level 1

1 Identity and Access Management

IAM password policies can prevent the reuse of a given password by the same user. It is recommended that the password policy prevent the reuse of passwords.

Perform the following to ensure the password policy is configured as prescribed: From Console: 1. Login to AWS Console (with appropriate permissions to View Identity Access Management Account Settings) 2. Go to IAM Service on the AWS Console 3. Click on Account Settings on the Left Pane 4. Ensure Prevent password reuse is checked 5. Ensure Number of passwords to remember is set to 24 From Command Line: aws iam get-account-password-policy Ensure the output of the above command includes PasswordReusePrevention: 24

Automated

Preventing password reuse increases account resiliency against brute force login attempts.

Perform the following to set the password policy as prescribed: From Console: 1. Login to AWS Console (with appropriate permissions to View Identity Access Management Account Settings) 2. Go to IAM Service on the AWS Console 3. Click on Account Settings on the Left Pane 4. Check Prevent password reuse 5. Set Number of passwords to remember is set to 24 From Command Line: aws iam update-account-password-policy --password-reuse-prevention 24 Note: All commands starting with aws iam update-account-password-policy can be combined into a single command.

Level 1

1 Identity and Access Management

Multi-Factor Authentication (MFA) adds an extra layer of authentication assurance beyond traditional credentials. With MFA enabled, when a user signs in to the AWS Console, they will be prompted for their user name and password as well as for an authentication code from their physical or virtual MFA token. It is recommended that MFA be enabled for all accounts that have a console password.

Perform the following to determine if a MFA device is enabled for all IAM users having a console password: From Console: 1. Open the IAM console at https://console.aws.amazon.com/iam/. 2. In the left pane, select Users 3. If the MFA or Password age columns are not visible in the table, click the gear icon at the upper right corner of the table and ensure a checkmark is next to both, then click Close. 4. Ensure that for each user where the Password age column shows a password age, the MFA column shows Virtual, U2F Security Key, or Hardware. From Command Line: 1. Run the following command (OSX/Linux/UNIX) to generate a list of all IAM users along with their password and MFA status: aws iam generate-credential-report aws iam get-credential-report --query 'Content' --output text | base64 -d | cut -d, -f1,4,8 2. The output of this command will produce a table similar to the following: user,password_enabled,mfa_active elise,false,false brandon,true,true rakesh,false,false helene,false,false paras,true,true anitha,false,false 3. For any column having password_enabled set to true , ensure mfa_active is also set to true.

AWS will soon end support for SMS multi-factor authentication (MFA). New customers are not allowed to use this feature. We recommend that existing customers switch to an alternative method of MFA.

Automated

Enabling MFA provides increased security for console access as it requires the authenticating principal to possess a device that displays a time-sensitive key and have knowledge of a credential.

Perform the following to enable MFA: From Console: 1. Sign in to the AWS Management Console and open the IAM console at 'https://console.aws.amazon.com/iam/' 2. In the left pane, select Users. 3. In the User Name list, choose the name of the intended MFA user. 4. Choose the Security Credentials tab, and then choose Manage MFA Device. 5. In the Manage MFA Device wizard, choose Virtual MFA device, and then choose Continue. IAM generates and displays configuration information for the virtual MFA device, including a QR code graphic. The graphic is a representation of the 'secret configuration key' that is available for manual entry on devices that do not support QR codes. 6. Open your virtual MFA application. (For a list of apps that you can use for hosting virtual MFA devices, see Virtual MFA Applications at https://aws.amazon.com/iam/details/mfa/#Virtual_MFA_Applications). If the virtual MFA application supports multiple accounts (multiple virtual MFA devices), choose the option to create a new account (a new virtual MFA device). 7. Determine whether the MFA app supports QR codes, and then do one of the following: - Use the app to scan the QR code. For example, you might choose the camera icon or choose an option similar to Scan code, and then use the device's camera to scan the code. - In the Manage MFA Device wizard, choose Show secret key for manual configuration, and then type the secret configuration key into your MFA application. When you are finished, the virtual MFA device starts generating one-time passwords. 8. In the Manage MFA Device wizard, in the MFA Code 1 box, type the one-time password that currently appears in the virtual MFA device. Wait up to 30 seconds for the device to generate a new one-time password. Then type the second one-time password into the MFA Code 2 box. 9. Click Assign MFA.

Forced IAM User Self-Service Remediation Amazon has published a pattern that requires users to set up MFA through self-service before they gain access to their complete set of permissions. Until they complete this step, they cannot access their full permissions. This pattern can be used for new AWS accounts. It can also be applied to existing accounts; it is recommended that users receive instructions and a grace period to complete MFA enrollment before active enforcement on existing AWS accounts.

Level 1

1 Identity and Access Management

AWS console defaults to no check boxes selected when creating a new IAM user. When creating the IAM User credentials you have to determine what type of access they require. Programmatic access: The IAM user might need to make API calls, use the AWS CLI, or use the Tools for Windows PowerShell. In that case, create an access key (access key ID and a secret access key) for that user. AWS Management Console access: If the user needs to access the AWS Management Console, create a password for the user.

Perform the following steps to determine if unused access keys were created upon user creation: From Console: 1. Login to the AWS Management Console 2. Click Services 3. Click IAM 4. Click on a User where column Password age and Access key age is not set to None 5. Click on Security credentials Tab 6. Compare the user Creation time to the Access Key Created date. 6. For any that match, the key was created during initial user setup. - Keys that were created at the same time as the user profile and do not have a last used date should be deleted. Refer to the remediation below. From Command Line: 1. Run the following command (OSX/Linux/UNIX) to generate a list of all IAM users along with their access keys utilization: aws iam generate-credential-report aws iam get-credential-report --query 'Content' --output text | base64 -d | cut -d, -f1,4,9,11,14,16 2. The output of this command will produce a table similar to the following: user,password_enabled,access_key_1_active,access_key_1_last_used_date,access_key_2_active,access_key_2_last_used_date elise,false,true,2015-04-16T15:14:00+00:00,false,N/A brandon,true,true,N/A,false,N/A rakesh,false,false,N/A,false,N/A helene,false,true,2015-11-18T17:47:00+00:00,false,N/A paras,true,true,2016-08-28T12:04:00+00:00,true,2016-03-04T10:11:00+00:00 anitha,true,true,2016-06-08T11:43:00+00:00,true,N/A 3. For any user having password_enabled set to true AND access_key_last_used_date set to N/A refer to the remediation below.

Manual

Requiring the additional steps to be taken by the user for programmatic access after their profile has been created will provide a stronger indication of intent that access keys are [a] necessary for their work and [b] that once the access key is established on an account, the keys may be in use somewhere in the organization. Note: Even if it is known the user will need access keys, require them to create the keys themselves or put in a support ticket to have them created as a separate step from user creation.

Perform the following to delete access keys that do not pass the audit: From Console: 1. Login to the AWS Management Console: 2. Click Services 3. Click IAM 4. Click on Users 5. Click on Security Credentials 6. As an Administrator - Click on the X (Delete) for keys that were created at the same time as the user profile but have not been used. 7. As an IAM User - Click on the X (Delete) for keys that were created at the same time as the user profile but have not been used. From Command Line: aws iam delete-access-key --access-key-id <access-key-id-listed> --user-name <users-name>

Credential report does not appear to contain Key Creation Date

Level 1

1 Identity and Access Management

AWS IAM users can access AWS resources using different types of credentials, such as passwords or access keys. It is recommended that all credentials that have been unused for 45 days or more be deactivated or removed.

Perform the following to determine if unused credentials exist: From Console: 1. Login to the AWS Management Console 2. Click Services 3. Click IAM 4. Click on Users 5. Click the Settings (gear) icon. 6. Select Console last sign-in, Access key last used, and Access Key Id 7. Click on Close 8. Check and ensure that Console last sign-in is less than 45 days ago. Note - Never means the user has never logged in. 9. Check and ensure that Access key age is less than 45 days and that Access key last used does not say None If the user hasn't signed into the Console in the last 45 days or Access keys are over 45 days old refer to the remediation. From Command Line: Download Credential Report: 1. Run the following commands: aws iam generate-credential-report aws iam get-credential-report --query 'Content' --output text | base64 -d | cut -d, -f1,4,5,6,9,10,11,14,15,16 | grep -v '^<root_account>' Ensure unused credentials do not exist: 2. For each user having password_enabled set to TRUE , ensure password_last_used_date is less than 45 days ago. - When password_enabled is set to TRUE and password_last_used is set to No_Information , ensure password_last_changed is less than 45 days ago. 3. For each user having an access_key_1_active or access_key_2_active to TRUE , ensure the corresponding access_key_n_last_used_date is less than 45 days ago. - When a user having an access_key_x_active (where x is 1 or 2) to TRUE and corresponding access_key_x_last_used_date is set to N/A, ensure access_key_x_last_rotated is less than 45 days ago.

Automated

Disabling or removing unnecessary credentials will reduce the window of opportunity for credentials associated with a compromised or abandoned account to be used.

From Console: Perform the following to manage Unused Password (IAM user console access) 1. Login to the AWS Management Console: 2. Click Services 3. Click IAM 4. Click on Users 5. Click on Security Credentials 6. Select user whose Console last sign-in is greater than 45 days 7. Click Security credentials 8. In section Sign-in credentials, Console password click Manage 9. Under Console Access select Disable 10. Click Apply Perform the following to deactivate Access Keys: 1. Login to the AWS Management Console: 2. Click Services 3. Click IAM 4. Click on Users 5. Click on Security Credentials 6. Select any access keys that are over 45 days old and that have been used and - Click on Make Inactive 7. Select any access keys that are over 45 days old and that have not been used and - Click the X to Delete

<root_account> is excluded in the audit since the root account should not be used for day-to-day business and would likely be unused for more than 45 days.

Level 1

1 Identity and Access Management

Access keys are long-term credentials for an IAM user or the AWS account 'root' user. You can use access keys to sign programmatic requests to the AWS CLI or AWS API (directly or using the AWS SDK)

From Console: 1. Sign in to the AWS Management Console and navigate to IAM dashboard at https://console.aws.amazon.com/iam/. 2. In the left navigation panel, choose Users. 3. Click on the IAM user name that you want to examine. 4. On the IAM user configuration page, select Security Credentials tab. 5. Under Access Keys section, in the Status column, check the current status for each access key associated with the IAM user. If the selected IAM user has more than one access key activated, then the user's access configuration does not adhere to security best practices, and the risk of accidental exposures increases. - Repeat steps 3-5 for each IAM user in your AWS account. From Command Line: 1. Run list-users command to list all IAM users within your account: aws iam list-users --query Users[*].UserName The command output should return an array that contains all your IAM user names. 2. Run list-access-keys command using the IAM user name list to return the current status of each access key associated with the selected IAM user: aws iam list-access-keys --user-name <user-name> The command output should expose the metadata (Username, AccessKeyId, Status, CreateDate) for each access key on that user account. 3. Check the Status property value for each key returned to determine each key's current state. If the Status property value for more than one IAM access key is set to Active, the user access configuration does not adhere to this recommendation; refer to the remediation below. - Repeat steps 2 and 3 for each IAM user in your AWS account.

Automated

One of the best ways to protect your account is to not allow users to have multiple access keys.

From Console: 1. Sign in to the AWS Management Console and navigate to IAM dashboard at https://console.aws.amazon.com/iam/. 2. In the left navigation panel, choose Users. 3. Click on the IAM user name that you want to examine. 4. On the IAM user configuration page, select Security Credentials tab. 5. In Access Keys section, choose one access key that is less than 90 days old. This should be the only active key used by this IAM user to access AWS resources programmatically. Test your application(s) to make sure that the chosen access key is working. 6. In the same Access Keys section, identify your non-operational access keys (other than the chosen one) and deactivate it by clicking the Make Inactive link. 7. If you receive the Change Key Status confirmation box, click Deactivate to switch off the selected key. 8. Repeat steps 3-7 for each IAM user in your AWS account. From Command Line: 1. Using the IAM user and access key information provided in the Audit CLI, choose one access key that is less than 90 days old. This should be the only active key used by this IAM user to access AWS resources programmatically. Test your application(s) to make sure that the chosen access key is working. 2. Run the update-access-key command below using the IAM user name and the non-operational access key IDs to deactivate the unnecessary key(s). Refer to the Audit section to identify the unnecessary access key ID for the selected IAM user Note - the command does not return any output: aws iam update-access-key --access-key-id <access-key-id> --status Inactive --user-name <user-name> 3. To confirm that the selected access key pair has been successfully deactivated run the list-access-keys audit command again for that IAM User: aws iam list-access-keys --user-name <user-name> - The command output should expose the metadata for each access key associated with the IAM user. If the non-operational key pair(s) Status is set to Inactive, the key has been successfully deactivated and the IAM user access configuration adheres now to this recommendation. 4. Repeat steps 1-3 for each IAM user in your AWS account.

Level 1

1 Identity and Access Management

Access keys consist of an access key ID and secret access key, which are used to sign programmatic requests that you make to AWS. AWS users need their own access keys to make programmatic calls to AWS from the AWS Command Line Interface (AWS CLI), Tools for Windows PowerShell, the AWS SDKs, or direct HTTP calls using the APIs for individual AWS services. It is recommended that all access keys be rotated regularly.

Perform the following to determine if access keys are rotated as prescribed: From Console: 1. Go to the Management Console (https://console.aws.amazon.com/iam) 2. Click on Users 3. For each user, go to Security Credentials 4. Review each key under Access Keys 5. For each key that shows Active for status, ensure that Created is less than or equal to 90 days ago. From Command Line: aws iam generate-credential-report aws iam get-credential-report --query 'Content' --output text | base64 -d The access_key_1_last_rotated and the access_key_2_last_rotated fields in this file notes the date and time, in ISO 8601 date-time format, when the user's access key was created or last changed. If the user does not have an active access key, the value in this field is N/A (not applicable).

Automated

Rotating access keys will reduce the window of opportunity for an access key that is associated with a compromised or terminated account to be used. Access keys should be rotated to ensure that data cannot be accessed with an old key which might have been lost, cracked, or stolen.

Perform the following to rotate access keys: From Console: 1. Go to the Management Console (https://console.aws.amazon.com/iam) 2. Click on Users 3. Click on Security Credentials 4. As an Administrator - Click on Make Inactive for keys that have not been rotated in 90 Days 5. As an IAM User - Click on Make Inactive or Delete for keys which have not been rotated or used in 90 Days 6. Click on Create Access Key 7. Update programmatic calls with new Access Key credentials From Command Line: 1. While the first access key is still active, create a second access key, which is active by default. Run the following command: aws iam create-access-key At this point, the user has two active access keys. 2. Update all applications and tools to use the new access key. 3. Determine whether the first access key is still in use by using this command: aws iam get-access-key-last-used 4. One approach is to wait several days and then check the old access key for any use before proceeding. Even if step 3 indicates no use of the old key, it is recommended that you do not immediately delete the first access key. Instead, change the state of the first access key to Inactive using this command: aws iam update-access-key 5. Use only the new access key to confirm that your applications are working. Any applications and tools that still use the original access key will stop working at this point because they no longer have access to AWS resources. If you find such an application or tool, you can switch its state back to Active to reenable the first access key. Then return to step 2 and update this application to use the new key. 6. After you wait some period of time to ensure that all applications and tools have been updated, you can delete the first access key with this command: aws iam delete-access-key

Level 1

1 Identity and Access Management

IAM users are granted access to services, functions, and data through IAM policies. There are four ways to define policies for a user: 1) Edit the user policy directly, also known as an inline or user policy; 2) attach a policy directly to a user; 3) add the user to an IAM group that has an attached policy; 4) add the user to an IAM group that has an inline policy. Only the third implementation is recommended.

Perform the following to determine if an inline policy is set or a policy is directly attached to users: 1. Run the following to get a list of IAM users: aws iam list-users --query 'Users[*].UserName' --output text 2. For each user returned, run the following command to determine if any policies are attached to them: aws iam list-attached-user-policies --user-name <iam_user> aws iam list-user-policies --user-name <iam_user> 3. If any policies are returned, the user has an inline policy or direct policy attachment.

Automated

Assigning IAM policies solely through groups unifies permissions management into a single, flexible layer that is consistent with organizational functional roles. By unifying permissions management, the likelihood of excessive permissions is reduced.

Perform the following to create an IAM group and assign a policy to it: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. In the navigation pane, click Groups and then click Create New Group. 3. In the Group Name box, type the name of the group and then click Next Step. 4. In the list of policies, select the check box for each policy that you want to apply to all members of the group. Then click Next Step. 5. Click Create Group. Perform the following to add a user to a given group: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. In the navigation pane, click Groups. 3. Select the group to add a user to. 4. Click Add Users To Group. 5. Select the users to be added to the group. 6. Click Add Users. Perform the following to remove a direct association between a user and policy: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. In the left navigation pane, click on Users. 3. For each user: - Select the user - Click on the Permissions tab - Expand Permissions policies - Click X for each policy; then click Detach or Remove (depending on policy type)

Level 1

1 Identity and Access Management

IAM policies are the means by which privileges are granted to users, groups, or roles. It is recommended and considered standard security advice to grant least privilege—that is, granting only the permissions required to perform a task. Determine what users need to do, and then craft policies for them that allow the users to perform only those tasks, instead of granting full administrative privileges.

Perform the following to determine existing policies: From Command Line: 1. Run the following to get a list of IAM policies: aws iam list-policies --only-attached --output text 2. For each policy returned, run the following command to determine if any policy is allowing full administrative privileges on the account: aws iam get-policy-version --policy-arn <policy_arn> --version-id <version> 3. In the output, the policy should not contain any Statement block with Effect: Allow and Action set to * and Resource set to *.

Automated

It's more secure to start with a minimum set of permissions and grant additional permissions as necessary, rather than starting with permissions that are too lenient and then attempting to tighten them later. Providing full administrative privileges instead of restricting access to the minimum set of permissions required for the user exposes resources to potentially unwanted actions. IAM policies that contain a statement with Effect: Allow and Action: * over Resource: * should be removed.

From Console: Perform the following to detach the policy that has full administrative privileges: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/iam/. 2. In the navigation pane, click Policies and then search for the policy name found in the audit step. 3. Select the policy that needs to be deleted. 4. In the policy action menu, select Detach. 5. Select all Users, Groups, Roles that have this policy attached. 6. Click Detach Policy. 7. Select the newly detached policy and select Delete. From Command Line: Perform the following to detach the policy that has full administrative privileges as found in the audit step: 1. Lists all IAM users, groups, and roles that the specified managed policy is attached to. aws iam list-entities-for-policy --policy-arn <policy_arn> 2. Detach the policy from all IAM Users: aws iam detach-user-policy --user-name <iam_user> --policy-arn <policy_arn> 3. Detach the policy from all IAM Groups: aws iam detach-group-policy --group-name <iam_group> --policy-arn <policy_arn> 4. Detach the policy from all IAM Roles: aws iam detach-role-policy --role-name <iam_role> --policy-arn <policy_arn>

Level 1

1 Identity and Access Management

AWS provides a support center that can be used for incident notification and response, as well as technical support and customer services. Create an IAM Role, with the appropriate policy assigned, to allow authorized users to manage incidents with AWS Support.

From Command Line: 1. List IAM policies, filter for the 'AWSSupportAccess' managed policy, and note the Arn element value: aws iam list-policies --query Policies[?PolicyName == 'AWSSupportAccess'] 2. Check if the 'AWSSupportAccess' policy is attached to any role: aws iam list-entities-for-policy --policy-arn arn:aws:iam::aws:policy/AWSSupportAccess 3. In the output, ensure PolicyRoles does not return empty. 'Example: Example: PolicyRoles: [ ]' If it returns empty refer to the remediation below.

All AWS Support plans include an unlimited number of account and billing support cases, with no long-term contracts. Support billing calculations are performed on a per-account basis for all plans. Enterprise Support plan customers have the option to include multiple enabled accounts in an aggregated monthly billing calculation. Monthly charges for the Business and Enterprise support plans are based on each month's AWS usage charges, subject to a monthly minimum, billed in advance. When assigning rights, keep in mind that other policies may grant access to Support as well. This may include AdministratorAccess and other policies including customer managed policies. Utilizing the AWS managed 'AWSSupportAccess' role is one simple way of ensuring that this permission is properly granted. To better support the principle of separation of duties, it would be best to only attach this role where necessary.

Automated

By implementing least privilege for access control, an IAM Role will require an appropriate IAM Policy to allow Support Center Access in order to manage Incidents with AWS Support.

From Command Line: 1. Create an IAM role for managing incidents with AWS: - Create a trust relationship policy document that allows <iam_user> to manage AWS incidents, and save it locally as /tmp/TrustPolicy.json: { Version: 2012-10-17, Statement: [ { Effect: Allow, Principal: { AWS: <iam_user> }, Action: sts:AssumeRole } ] } 2. Create the IAM role using the above trust policy: aws iam create-role --role-name <aws_support_iam_role> --assume-role-policy-document file:///tmp/TrustPolicy.json 3. Attach 'AWSSupportAccess' managed policy to the created IAM role: aws iam attach-role-policy --policy-arn arn:aws:iam::aws:policy/AWSSupportAccess --role-name <aws_support_iam_role>

AWSSupportAccess policy is a global AWS resource. It has same ARN as arn:aws:iam::aws:policy/AWSSupportAccess for every account.

Level 2

1 Identity and Access Management

AWS access from within AWS instances can be done by either encoding AWS keys into AWS API calls or by assigning the instance to a role which has an appropriate permissions policy for the required access. AWS Access means accessing the APIs of AWS in order to access AWS resources or manage AWS account resources.

First, check if the instance has any API secrets stored using Secret Scanning. Currently, AWS does not have a solution for this. You can use open-source tools like TruffleHog to scan for secrets in the EC2 instance. If a secret is found, then assign the role to the instance. From Console: 1. Sign in to the AWS Management Console and navigate to the EC2 dashboard at https://console.aws.amazon.com/ec2/. 2. In the left navigation panel, choose Instances. 3. Select the EC2 instance you want to examine. 4. Select Actions. 5. Select View details. 6. Select Security in the lower panel. - If the value for Instance profile arn is an instance profile ARN, then an instance profile (that contains an IAM role) is attached. - If the value for IAM Role is blank, no role is attached. - If the value for IAM Role contains a role, a role is attached. - If the value for IAM Role is No roles attached to instance profile: <Instance-Profile-Name>, then an instance profile is attached to the instance, but it does not contain an IAM role. 7. Repeat steps 3 to 6 for each EC2 instance in your AWS account. From Command Line: 1. Run the describe-instances command to list all EC2 instance IDs in the selected AWS region: aws ec2 describe-instances --region <region-name> --query 'Reservations[*].Instances[*].InstanceId' 2. Run the describe-instances command again for each EC2 instance using the IamInstanceProfile identifier in the query filter to check if an IAM role is attached: aws ec2 describe-instances --region <region-name> --instance-id <Instance-ID> --query 'Reservations[*].Instances[*].IamInstanceProfile' 3. If an IAM role is attached, the command output will show the IAM instance profile ARN and ID. 4. Repeat steps 2 and 3 for each EC2 instance in your AWS account.

Automated

AWS IAM roles reduce the risks associated with sharing and rotating credentials that can be used outside of AWS itself. Compromised credentials can be used from outside the AWS account to which they provide access. In contrast, to leverage role permissions, an attacker would need to gain and maintain access to a specific instance to use the privileges associated with it. Additionally, if credentials are encoded into compiled applications or other hard-to-change mechanisms, they are even less likely to be properly rotated due to the risks of service disruption. As time passes, credentials that cannot be rotated are more likely to be known by an increasing number of individuals who no longer work for the organization that owns the credentials.

From Console: 1. Sign in to the AWS Management Console and navigate to the EC2 dashboard at https://console.aws.amazon.com/ec2/. 2. In the left navigation panel, choose Instances. 3. Select the EC2 instance you want to modify. 4. Click Actions. 5. Click Security. 6. Click Modify IAM role. 7. Click Create new IAM role if a new IAM role is required. 8. Select the IAM role you want to attach to your instance in the IAM role dropdown. 9. Click Update IAM role. 10. Repeat steps 3 to 9 for each EC2 instance in your AWS account that requires an IAM role to be attached. From Command Line: 1. Run the describe-instances command to list all EC2 instance IDs in the selected AWS region: aws ec2 describe-instances --region <region-name> --query 'Reservations[*].Instances[*].InstanceId' 2. Run the associate-iam-instance-profile command to attach an instance profile (which is attached to an IAM role) to the EC2 instance: aws ec2 associate-iam-instance-profile --region <region-name> --instance-id <Instance-ID> --iam-instance-profile Name=Instance-Profile-Name 3. Run the describe-instances command again for the recently modified EC2 instance. The command output should return the instance profile ARN and ID: aws ec2 describe-instances --region <region-name> --instance-id <Instance-ID> --query 'Reservations[*].Instances[*].IamInstanceProfile' 4. Repeat steps 2 and 3 for each EC2 instance in your AWS account that requires an IAM role to be attached.

Level 1

1 Identity and Access Management

To enable HTTPS connections to your website or application in AWS, you need an SSL/TLS server certificate. You can use AWS Certificate Manager (ACM) or IAM to store and deploy server certificates. Use IAM as a certificate manager only when you must support HTTPS connections in a region that is not supported by ACM. IAM securely encrypts your private keys and stores the encrypted version in IAM SSL certificate storage. IAM supports deploying server certificates in all regions, but you must obtain your certificate from an external provider for use with AWS. You cannot upload an ACM certificate to IAM. Additionally, you cannot manage your certificates from the IAM Console.

By default, expired certificates will not be deleted.

From Console: Getting the certificate expiration information via the AWS Management Console is not currently supported. To request information about the SSL/TLS certificates stored in IAM through the AWS API, use the Command Line Interface (CLI). From Command Line: Run the list-server-certificates command to list all the IAM-stored server certificates: aws iam list-server-certificates The command output should return an array that contains all the SSL/TLS certificates currently stored in IAM and their metadata (name, ID, expiration date, etc): { ServerCertificateMetadataList: [ { ServerCertificateId: EHDGFRW7EJFYTE88D, ServerCertificateName: MyServerCertificate, Expiration: 2018-07-10T23:59:59Z, Path: /, Arn: arn:aws:iam::012345678910:server-certificate/MySSLCertificate, UploadDate: 2018-06-10T11:56:08Z } ] } Verify the ServerCertificateName and Expiration parameter value (expiration date) for each SSL/TLS certificate returned by the list-server-certificates command and determine if there are any expired server certificates currently stored in AWS IAM. If so, use the AWS API to remove them. If this command returns: { { ServerCertificateMetadataList: [] } This means that there are no expired certificates; it does not mean that no certificates exist.

Deleting the certificate could have implications for your application if you are using an expired server certificate with Elastic Load Balancing, CloudFront, etc. You must make configurations in the respective services to ensure there is no interruption in application functionality.

Automated

Removing expired SSL/TLS certificates eliminates the risk that an invalid certificate will be deployed accidentally to a resource such as AWS Elastic Load Balancer (ELB), which can damage the credibility of the application/website behind the ELB. As a best practice, it is recommended to delete expired certificates.

From Console: Removing expired certificates via AWS Management Console is not currently supported. To delete SSL/TLS certificates stored in IAM through the AWS API, use the Command Line Interface (CLI). From Command Line: To delete an expired certificate, run the following command by replacing <CERTIFICATE_NAME> with the name of the certificate to delete: aws iam delete-server-certificate --server-certificate-name <CERTIFICATE_NAME> When the preceding command is successful, it does not return any output.

Level 1

1 Identity and Access Management

Enable the IAM External Access Analyzer regarding all resources in each active AWS region. IAM Access Analyzer is a technology introduced at AWS reinvent 2019. After the Analyzer is enabled in IAM, scan results are displayed on the console showing the accessible resources. Scans show resources that other accounts and federated users can access, such as KMS keys and IAM roles. The results allow you to determine whether an unintended user is permitted, making it easier for administrators to monitor least privilege access. Access Analyzer analyzes only the policies that are applied to resources in the same AWS Region.

From Console: 1. Open the IAM console at https://console.aws.amazon.com/iam/ 2. Under Access analyzer choose External Access 3. Ensure that at least one analyzer is present 4. Ensure that the STATUS is set to Active 5. Repeat these steps for each active region From Command Line: 1. Run the following command: aws accessanalyzer list-analyzers type --<Account|Organization> | grep status 2. Ensure that at least one Analyzer's status is set to ACTIVE. 3. Repeat the steps above for each active region. If an Access Analyzer is not listed for each region or the status is not set to active refer to the remediation procedure below.

Automated

AWS IAM External Access Analyzer helps you identify the resources in your organization and accounts, such as Amazon S3 buckets or IAM roles, that are shared with external entities. This allows you to identify unintended access to your resources and data. Access Analyzer identifies resources that are shared with external principals by using logic-based reasoning to analyze the resource-based policies in your AWS environment. IAM External Access Analyzer continuously monitors all policies for S3 buckets, IAM roles, KMS (Key Management Service) keys, AWS Lambda functions, Amazon SQS (Simple Queue Service) queues and more

From Console: Perform the following to enable IAM Access Analyzer for IAM policies: 1. Open the IAM console at https://console.aws.amazon.com/iam/. 2. Choose Access analyzer. 3. Choose Create external access analyzer. 4. On the Create analyzer page, confirm that the Region displayed is the Region where you want to enable Access Analyzer. 5. Optionally enter a name for the analyzer. 6. Optionally add any tags that you want to apply to the analyzer. 7. Choose Create Analyzer. 8. Repeat these step for each active region. From Command Line: Run the following command: aws accessanalyzer create-analyzer --analyzer-name <NAME> --type <ACCOUNT|ORGANIZATION> Repeat this command for each active region. Note: The IAM Access Analyzer is successfully configured only when the account you use has the necessary permissions.

Some regions in AWS are enabled by default, while others are disabled by default. Regions introduced prior to March 20, 2019, are enabled by default and cannot be disabled. Regions introduced afterward can be disabled by default. For more information on managing AWS Regions, please see AWS's documentation on managing AWS Regions.

Level 2

1 Identity and Access Management

In multi-account environments, IAM user centralization facilitates greater user control. User access beyond the initial account is then provided via role assumption. Centralization of users can be accomplished through federation with an external identity provider or through the use of AWS Organizations.

For multi-account AWS environments with an external identity provider: 1. Determine the master account for identity federation or IAM user management 2. Login to that account through the AWS Management Console 3. Click Services 4. Click IAM 5. Click Identity providers 6. Verify the configuration For multi-account AWS environments with an external identity provider, as well as for those implementing AWS Organizations without an external identity provider: 1. Determine all accounts that should not have local users present 2. Log into the AWS Management Console 3. Switch role into each identified account 4. Click Services 5. Click IAM 6. Click Users 7. Confirm that no IAM users representing individuals are present

Manual

Centralizing IAM user management to a single identity store reduces complexity and thus the likelihood of access management errors.

The remediation procedure will vary based on each individual organization's implementation of identity federation and/or AWS Organizations, with the acceptance criteria that no non-service IAM users and non-root accounts are present outside the account providing centralized IAM user management.

Level 1

1 Identity and Access Management

AWS CloudShell is a convenient way of running CLI commands against AWS services; a managed IAM policy ('AWSCloudShellFullAccess') provides full access to CloudShell, which allows file upload and download capability between a user's local system and the CloudShell environment. Within the CloudShell environment, a user has sudo permissions and can access the internet. Therefore, it is feasible to install file transfer software, for example, and move data from CloudShell to external internet servers.

From Console 1. Open the IAM console at https://console.aws.amazon.com/iam/ 2. In the left pane, select Policies 3. Search for and select AWSCloudShellFullAccess 4. On the Entities attached tab, ensure that there are no entities using this policy From Command Line 1. List IAM policies, filter for the 'AWSCloudShellFullAccess' managed policy, and note the Arn element value: aws iam list-policies --query Policies[?PolicyName == 'AWSCloudShellFullAccess'] 2. Check if the 'AWSCloudShellFullAccess' policy is attached to any role: aws iam list-entities-for-policy --policy-arn arn:aws:iam::aws:policy/AWSCloudShellFullAccess 3. In the output, ensure PolicyRoles returns empty. 'Example: Example: PolicyRoles: [ ]' If it does not return empty, refer to the remediation below. Note: Keep in mind that other policies may grant access.

Manual

Access to this policy should be restricted, as it presents a potential channel for data exfiltration by malicious cloud admins who are given full permissions to the service. AWS documentation describes how to create a more restrictive IAM policy that denies file transfer permissions.

From Console 1. Open the IAM console at https://console.aws.amazon.com/iam/ 2. In the left pane, select Policies 3. Search for and select AWSCloudShellFullAccess 4. On the Entities attached tab, for each item, check the box and select Detach

Level 2

2 Storage

2.1 Simple Storage Service (S3)

At the Amazon S3 bucket level, you can configure permissions through a bucket policy, making the objects accessible only through HTTPS.

Both HTTP and HTTPS requests are allowed.

To allow access to HTTPS, you can use a bucket policy with the effect allow and a condition that checks for the key aws:SecureTransport: true. This means that HTTPS requests are allowed, but it does not deny HTTP requests. To explicitly deny HTTP access, ensure that there is also a bucket policy with the effect deny that contains the key aws:SecureTransport: false. You may also require TLS by setting a policy to deny any version lower than the one you wish to require, using the condition NumericLessThan and the key s3:TlsVersion: 1.2. From Console: 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Select the check box next to the Bucket. 3. Click on 'Permissions', then click on Bucket Policy. 4. Ensure that a policy is listed that matches either: { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: arn:aws:s3:::<bucket_name>/*, Condition: { Bool: { aws:SecureTransport: false } } } or { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: [ arn:aws:s3:::<bucket_name>, arn:aws:s3:::<bucket_name>/* ], Condition: { NumericLessThan: { s3:TlsVersion: 1.2 } } } <optional> and <bucket_name> will be specific to your account, and TLS version will be site/policy specific to your organisation. 5. Repeat for all the buckets in your AWS account. From Command Line: 1. List all of the S3 Buckets aws s3 ls 2. Using the list of buckets, run this command on each of them: aws s3api get-bucket-policy --bucket <bucket_name> | grep aws:SecureTransport or aws s3api get-bucket-policy --bucket <bucket_name> | grep s3:TlsVersion NOTE : If an error is thrown by the CLI, it means no policy has been configured for the specified S3 bucket, and that by default it is allowing both HTTP and HTTPS requests. 3. Confirm that aws:SecureTransport is set to false (such as aws:SecureTransport:false) or that s3:TlsVersion has a site-specific value. 4. Confirm that the policy line has Effect set to Deny 'Effect:Deny'

Automated

By default, Amazon S3 allows both HTTP and HTTPS requests. To ensure that access to Amazon S3 objects is only permitted through HTTPS, you must explicitly deny HTTP requests. Bucket policies that allow HTTPS requests without explicitly denying HTTP requests will not comply with this recommendation.

From Console: 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Select the check box next to the Bucket. 3. Click on 'Permissions'. 4. Click 'Bucket Policy'. 5. Add either of the following to the existing policy, filling in the required information: { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: arn:aws:s3:::<bucket_name>/*, Condition: { Bool: { aws:SecureTransport: false } } } or { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: [ arn:aws:s3:::<bucket_name>, arn:aws:s3:::<bucket_name>/* ], Condition: { NumericLessThan: { s3:TlsVersion: 1.2 } } } 6. Save 7. Repeat for all the buckets in your AWS account that contain sensitive data. From Console Using AWS Policy Generator: 1. Repeat steps 1-4 above. 2. Click on Policy Generator at the bottom of the Bucket Policy Editor. 3. Select Policy Type S3 Bucket Policy. 4. Add Statements: - Effect = Deny - Principal = * - AWS Service = Amazon S3 - Actions = * - Amazon Resource Name = <ARN of the S3 Bucket> 5. Generate Policy. 6. Copy the text and add it to the Bucket Policy. From Command Line: 1. Export the bucket policy to a json file: aws s3api get-bucket-policy --bucket <bucket_name> --query Policy --output text > policy.json 2. Modify the policy.json file by adding either of the following: { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: arn:aws:s3:::<bucket_name>/*, Condition: { Bool: { aws:SecureTransport: false } } } or { Sid: <optional>, Effect: Deny, Principal: *, Action: s3:*, Resource: [ arn:aws:s3:::<bucket_name>, arn:aws:s3:::<bucket_name>/* ], Condition: { NumericLessThan: { s3:TlsVersion: 1.2 } } } 3. Apply this modified policy back to the S3 bucket: aws s3api put-bucket-policy --bucket <bucket_name> --policy file://policy.json

Level 2

2 Storage

2.1 Simple Storage Service (S3)

Once MFA Delete is enabled on your sensitive and classified S3 bucket, it requires the user to provide two forms of authentication.

Perform the steps below to confirm that MFA delete is configured on an S3 bucket: From Console: 1. Login to the S3 console at https://console.aws.amazon.com/s3/. 2. Click the check box next to the name of the bucket you want to confirm. 3. In the window under Properties: - Confirm that Versioning is Enabled - Confirm that MFA Delete is Enabled From Command Line: 1. Run the get-bucket-versioning command: aws s3api get-bucket-versioning --bucket my-bucket Example output: <VersioningConfiguration xmlns=http://s3.amazonaws.com/doc/2006-03-01/> <Status>Enabled</Status> <MfaDelete>Enabled</MfaDelete> </VersioningConfiguration> If the console or CLI output does not show that Versioning and MFA Delete are enabled, please refer to the remediation below.

Enabling MFA delete on an S3 bucket could require additional administrator oversight. Enabling MFA delete may impact other services that automate the creation and/or deletion of S3 buckets.

Manual

Adding MFA delete to an S3 bucket requires additional authentication when you change the version state of your bucket or delete an object version, adding another layer of security in the event your security credentials are compromised or unauthorized access is granted.

Perform the steps below to enable MFA delete on an S3 bucket: Note: - You cannot enable MFA Delete using the AWS Management Console; you must use the AWS CLI or API. - You must use your 'root' account to enable MFA Delete on S3 buckets. From Command line: 1. Run the s3api put-bucket-versioning command: aws s3api put-bucket-versioning --profile my-root-profile --bucket Bucket_Name --versioning-configuration Status=Enabled,MFADelete=Enabled --mfa “arn:aws:iam::aws_account_id:mfa/root-account-mfa-device passcode”

Level 2

2 Storage

2.1 Simple Storage Service (S3)

Amazon S3 buckets can contain sensitive data that, for security purposes, should be discovered, monitored, classified, and protected. Macie, along with other third-party tools, can automatically provide an inventory of Amazon S3 buckets.

Perform the following steps to determine if Macie is running: From Console: 1. Login to the Macie console at https://console.aws.amazon.com/macie/. 2. In the left hand pane, click on By job under findings. 3. Confirm that you have a job set up for your S3 buckets. When you log into the Macie console, if you are not taken to the summary page and do not have a job set up and running, then refer to the remediation procedure below. If you are using a third-party tool to manage and protect your S3 data, you meet this recommendation.

There is a cost associated with using Amazon Macie, and there is typically a cost associated with third-party tools that perform similar processes and provide protection.

Manual

Using a cloud service or third-party software to continuously monitor and automate the process of data discovery and classification for S3 buckets through machine learning and pattern matching is a strong defense in protecting that information. Amazon Macie is a fully managed data security and privacy service that uses machine learning and pattern matching to discover and protect your sensitive data in AWS.

Perform the steps below to enable and configure Amazon Macie: From Console: 1. Log on to the Macie console at https://console.aws.amazon.com/macie/. 2. Click Get started. 3. Click Enable Macie. Set up a repository for sensitive data discovery results: 1. In the left pane, under Settings, click Discovery results. 2. Make sure Create bucket is selected. 3. Create a bucket and enter a name for it. The name must be unique across all S3 buckets, and it must start with a lowercase letter or a number. 4. Click Advanced. 5. For block all public access, make sure Yes is selected. 6. For KMS encryption, specify the AWS KMS key that you want to use to encrypt the results. The key must be a symmetric customer master key (CMK) that is in the same region as the S3 bucket. 7. Click Save. Create a job to discover sensitive data: 1. In the left pane, click S3 buckets. Macie displays a list of all the S3 buckets for your account. 2. Check the box for each bucket that you want Macie to analyze as part of the job. 3. Click Create job. 4. Click Quick create. 5. For the Name and Description step, enter a name and, optionally, a description of the job. 6. Click Next. 7. For the Review and create step, click Submit. Review your findings: 1. In the left pane, click Findings. 2. To view the details of a specific finding, choose any field other than the check box for the finding. If you are using a third-party tool to manage and protect your S3 data, follow the vendor documentation for implementing and configuring that tool.

Level 1

2 Storage

2.1 Simple Storage Service (S3)

Amazon S3 provides Block public access (bucket settings) and Block public access (account settings) to help you manage public access to Amazon S3 resources. By default, S3 buckets and objects are created with public access disabled. However, an IAM principal with sufficient S3 permissions can enable public access at the bucket and/or object level. While enabled, Block public access (bucket settings) prevents an individual bucket and its contained objects from becoming publicly accessible. Similarly, Block public access (account settings) prevents all buckets and their contained objects from becoming publicly accessible across the entire account.

If utilizing Block Public Access (bucket settings) From Console: 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Select the check box next to a bucket. 3. Click on 'Edit public access settings'. 4. Ensure that the block public access settings are configured appropriately for this bucket. 5. Repeat for all the buckets in your AWS account. From Command Line: 1. List all of the S3 buckets: aws s3 ls 2. Find the public access settings for a specific bucket: aws s3api get-public-access-block --bucket <bucket-name> Output if Block Public Access is enabled: { PublicAccessBlockConfiguration: { BlockPublicAcls: true, IgnorePublicAcls: true, BlockPublicPolicy: true, RestrictPublicBuckets: true } } If the output reads false for the separate configuration settings, then proceed with the remediation. If utilizing Block Public Access (account settings) From Console: 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Choose Block public access (account settings). 3. Ensure that the block public access settings are configured appropriately for your AWS account. From Command Line: To check the block public access settings for this account, run the following command: aws s3control get-public-access-block --account-id <account-id> --region <region-name> Output if Block Public Access is enabled: { PublicAccessBlockConfiguration: { IgnorePublicAcls: true, BlockPublicPolicy: true, BlockPublicAcls: true, RestrictPublicBuckets: true } } If the output reads false for the separate configuration settings, then proceed with the remediation.

When you apply Block Public Access settings to an account, the settings apply to all AWS regions globally. The settings may not take effect in all regions immediately or simultaneously, but they will eventually propagate to all regions.

Automated

Amazon S3 Block public access (bucket settings) prevents the accidental or malicious public exposure of data contained within the respective bucket(s). Amazon S3 Block public access (account settings) prevents the accidental or malicious public exposure of data contained within all buckets of the respective AWS account. Whether to block public access to all or some buckets is an organizational decision that should be based on data sensitivity, least privilege, and use case.

If utilizing Block Public Access (bucket settings) From Console: 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Select the check box next to a bucket. 3. Click 'Edit public access settings'. 4. Click 'Block all public access' 5. Repeat for all the buckets in your AWS account that contain sensitive data. From Command Line: 1. List all of the S3 buckets: aws s3 ls 2. Enable Block Public Access on a specific bucket: aws s3api put-public-access-block --bucket <bucket-name> --public-access-block-configuration BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true If utilizing Block Public Access (account settings) From Console: If the output reads true for the separate configuration settings, then Block Public Access is enabled on the account. 1. Login to the AWS Management Console and open the Amazon S3 console using https://console.aws.amazon.com/s3/. 2. Click Block Public Access (account settings). 3. Click Edit to change the block public access settings for all the buckets in your AWS account. 4. Update the settings and click Save. For details about each setting, pause on the i icons. 5. When you're asked for confirmation, enter confirm. Then click Confirm to save your changes. From Command Line: To enable Block Public Access for this account, run the following command: aws s3control put-public-access-block --public-access-block-configuration BlockPublicAcls=true, IgnorePublicAcls=true, BlockPublicPolicy=true, RestrictPublicBuckets=true --account-id <account-id>

Level 1

2 Storage

2.2 Relational Database Service (RDS)

Amazon RDS encrypted DB instances use the industry-standard AES-256 encryption algorithm to encrypt your data on the server that hosts your Amazon RDS DB instances. After your data is encrypted, Amazon RDS handles the authentication of access and the decryption of your data transparently, with minimal impact on performance.

From Console: 1. Login to the AWS Management Console and open the RDS dashboard at https://console.aws.amazon.com/rds/. 2. In the navigation pane, under RDS dashboard, click Databases. 3. Select the RDS instance that you want to examine. 4. Click Instance Name to see details, then select the Configuration tab. 5. Under Configuration Details, in the Storage pane, search for the Encryption Enabled status. 6. If the current status is set to Disabled, encryption is not enabled for the selected RDS database instance. 7. Repeat steps 2 to 6 to verify the encryption status of other RDS instances in the same region. 8. Change the region from the top of the navigation bar, and repeat the audit steps for other regions. From Command Line: 1. Run the describe-db-instances command to list all the RDS database instance names available in the selected AWS region. The output will return each database instance identifier (name): aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. Run the describe-db-instances command again, using an RDS instance identifier returned from step 1, to determine if the selected database instance is encrypted. The output should return the encryption status True or False: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-name> --query 'DBInstances[*].StorageEncrypted' 3. If the StorageEncrypted parameter value is False, encryption is not enabled for the selected RDS database instance. 4. Repeat steps 1 to 3 to audit each RDS instance, and change the region to verify RDS instances in other regions.

Automated

Databases are likely to hold sensitive and critical data; therefore, it is highly recommended to implement encryption to protect your data from unauthorized access or disclosure. With RDS encryption enabled, the data stored on the instance's underlying storage, the automated backups, read replicas, and snapshots are all encrypted.

From Console: 1. Login to the AWS Management Console and open the RDS dashboard at https://console.aws.amazon.com/rds/. 2. In the left navigation panel, click on Databases. 3. Select the Database instance that needs to be encrypted. 4. Click the Actions button placed at the top right and select Take Snapshot. 5. On the Take Snapshot page, enter the name of the database for which you want to take a snapshot in the Snapshot Name field and click on Take Snapshot. 6. Select the newly created snapshot, click the Action button placed at the top right, and select Copy snapshot from the Action menu. 7. On the Make Copy of DB Snapshot page, perform the following: - In the New DB Snapshot Identifier field, enter a name for the new snapshot. - Check Copy Tags. The new snapshot must have the same tags as the source snapshot. - Select Yes from the Enable Encryption dropdown list to enable encryption. You can choose to use the AWS default encryption key or a custom key from the Master Key dropdown list. 8. Click Copy Snapshot to create an encrypted copy of the selected instance's snapshot. 9. Select the new Snapshot Encrypted Copy and click the Action button located at the top right. Then, select the Restore Snapshot option from the Action menu. This will restore the encrypted snapshot to a new database instance. 10. On the Restore DB Instance page, enter a unique name for the new database instance in the DB Instance Identifier field. 11. Review the instance configuration details and click Restore DB Instance. 12. As the new instance provisioning process is completed, you can update the application configuration to refer to the endpoint of the new encrypted database instance. Once the database endpoint is changed at the application level, you can remove the unencrypted instance. From Command Line: 1. Run the describe-db-instances command to list the names of all RDS database instances in the selected AWS region. The command output should return database instance identifiers: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. Run the create-db-snapshot command to create a snapshot for a selected database instance. The command output will return the new snapshot with name DB Snapshot Name: aws rds create-db-snapshot --region <region-name> --db-snapshot-identifier <db-snapshot-name> --db-instance-identifier <db-name> 3. Now run the list-aliases command to list the KMS key aliases available in a specified region. The command output should return each key alias currently available. For our RDS encryption activation process, locate the ID of the AWS default KMS key: aws kms list-aliases --region <region-name> 4. Run the copy-db-snapshot command using the default KMS key ID for the RDS instances returned earlier to create an encrypted copy of the database instance snapshot. The command output will return the encrypted instance snapshot configuration: aws rds copy-db-snapshot --region <region-name> --source-db-snapshot-identifier <db-snapshot-name> --target-db-snapshot-identifier <db-snapshot-name-encrypted> --copy-tags --kms-key-id <kms-id-for-rds> 5. Run the restore-db-instance-from-db-snapshot command to restore the encrypted snapshot created in the previous step to a new database instance. If successful, the command output should return the configuration of the new encrypted database instance: aws rds restore-db-instance-from-db-snapshot --region <region-name> --db-instance-identifier <db-name-encrypted> --db-snapshot-identifier <db-snapshot-name-encrypted> 6. Run the describe-db-instances command to list all RDS database names available in the selected AWS region. The output will return the database instance identifier names. Select the encrypted database name that we just created, db-name-encrypted: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 7. Run the describe-db-instances command again using the RDS instance identifier returned earlier to determine if the selected database instance is encrypted. The command output should indicate that the encryption status is True: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-name-encrypted> --query 'DBInstances[*].StorageEncrypted'

Level 1

2 Storage

2.2 Relational Database Service (RDS)

Ensure that RDS database instances have the Auto Minor Version Upgrade flag enabled to automatically receive minor engine upgrades during the specified maintenance window. This way, RDS instances can obtain new features, bug fixes, and security patches for their database engines.

From Console: 1. Log in to the AWS management console and navigate to the RDS dashboard at https://console.aws.amazon.com/rds/. 2. In the left navigation panel, click Databases. 3. Select the RDS instance that you want to examine. 4. Click on the Maintenance and backups panel. 5. Under the Maintenance section, search for the Auto Minor Version Upgrade status. - If the current status is Disabled, it means that the feature is not enabled, and the minor engine upgrades released will not be applied to the selected RDS instance. From Command Line: 1. Run the describe-db-instances command to list all RDS database names available in the selected AWS region: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. The command output should return each database instance identifier. 3. Run the describe-db-instances command again using a RDS instance identifier returned earlier to determine the Auto Minor Version Upgrade status for the selected instance: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-instance-identifier> --query 'DBInstances[*].AutoMinorVersionUpgrade' 4. The command output should return the current status of the feature. If the current status is set to true, the feature is enabled and the minor engine upgrades will be applied to the selected RDS instance.

Automated

AWS RDS will occasionally deprecate minor engine versions and provide new ones for upgrades. When the last version number within a release is replaced, the changed version is considered minor. With the Auto Minor Version Upgrade feature enabled, version upgrades will occur automatically during the specified maintenance window, allowing your RDS instances to receive new features, bug fixes, and security patches for their database engines.

From Console: 1. Log in to the AWS management console and navigate to the RDS dashboard at https://console.aws.amazon.com/rds/. 2. In the left navigation panel, click Databases. 3. Select the RDS instance that you want to update. 4. Click on the Modify button located at the top right side. 5. On the Modify DB Instance: <instance identifier> page, In the Maintenance section, select Auto minor version upgrade and click the Yes radio button. 6. At the bottom of the page, click Continue, and check Apply Immediately to apply the changes immediately, or select Apply during the next scheduled maintenance window to avoid any downtime. 7. Review the changes and click Modify DB Instance. The instance status should change from available to modifying and back to available. Once the feature is enabled, the Auto Minor Version Upgrade status should change to Yes. From Command Line: 1. Run the describe-db-instances command to list all RDS database instance names available in the selected AWS region: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. The command output should return each database instance identifier. 3. Run the modify-db-instance command to modify the configuration of a selected RDS instance. This command will apply the changes immediately. Remove --apply-immediately to apply changes during the next scheduled maintenance window and avoid any downtime: aws rds modify-db-instance --region <region-name> --db-instance-identifier <db-instance-identifier> --auto-minor-version-upgrade --apply-immediately 4. The command output should reveal the new configuration metadata for the RDS instance, including the AutoMinorVersionUpgrade parameter value. 5. Run the describe-db-instances command to check if the Auto Minor Version Upgrade feature has been successfully enabled: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-instance-identifier> --query 'DBInstances[*].AutoMinorVersionUpgrade' 6. The command output should return the feature's current status set to true, indicating that the feature is enabled, and that the minor engine upgrades will be applied to the selected RDS instance.

Level 1

2 Storage

2.2 Relational Database Service (RDS)

Ensure and verify that the RDS database instances provisioned in your AWS account restrict unauthorized access in order to minimize security risks. To restrict access to any RDS database instance, you must disable the Publicly Accessible flag for the database and update the VPC security group associated with the instance.

From Console: 1. Log in to the AWS management console and navigate to the RDS dashboard at https://console.aws.amazon.com/rds/. 2. Under the navigation panel, on the RDS dashboard, click Databases. 3. Select the RDS instance that you want to examine. 4. Click Instance Name from the dashboard, under Connectivity and Security. 5. In the Security section, check if the Publicly Accessible flag status is set to Yes. 6. Follow the steps below to check database subnet access: - In the networking section, click the subnet link under Subnets. - The link will redirect you to the VPC Subnets page. - Select the subnet listed on the page and click the Route Table tab from the dashboard bottom panel. - If the route table contains any entries with the destination CIDR block set to 0.0.0.0/0 and an Internet Gateway attached, the selected RDS database instance was provisioned inside a public subnet; therefore, it is not running within a logically isolated environment and can be accessed from the Internet. 7. Repeat steps 3-6 to determine the configuration of other RDS database instances provisioned in the current region. 8. Change the AWS region from the navigation bar and repeat the audit process for other regions. From Command Line: 1. Run the describe-db-instances command to list all available RDS database names in the selected AWS region: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. The command output should return each database instance identifier. 3. Run the describe-db-instances command again, using the PubliclyAccessible parameter as a query filter to reveal the status of the database instance's Publicly Accessible flag: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-instance-name> --query 'DBInstances[*].PubliclyAccessible' 4. Check the Publicly Accessible parameter status. If the Publicly Accessible flag is set to Yes, then the selected RDS database instance is publicly accessible and insecure. Follow the steps mentioned below to check database subnet access. 5. Run the describe-db-instances command again using the RDS database instance identifier that you want to check, along with the appropriate filtering to describe the VPC subnet(s) associated with the selected instance: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-instance-name> --query 'DBInstances[*].DBSubnetGroup.Subnets[]' - The command output should list the subnets available in the selected database subnet group. 6. Run the describe-route-tables command using the ID of the subnet returned in the previous step to describe the routes of the VPC route table associated with the selected subnet: aws ec2 describe-route-tables --region <region-name> --filters Name=association.subnet-id,Values=<subnet-id> --query 'RouteTables[*].Routes[]' - If the command returns the route table associated with the database instance subnet ID, check the values of the GatewayId and DestinationCidrBlock attributes returned in the output. If the route table contains any entries with the GatewayId value set to igw-xxxxxxxx and the DestinationCidrBlock value set to 0.0.0.0/0, the selected RDS database instance was provisioned within a public subnet. - Or, if the command returns empty results, the route table is implicitly associated with the subnet; therefore, the audit process continues with the next step. 7. Run the describe-db-instances command again using the RDS database instance identifier that you want to check, along with the appropriate filtering to describe the VPC ID associated with the selected instance: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-instance-name> --query 'DBInstances[*].DBSubnetGroup.VpcId' - The command output should show the VPC ID in the selected database subnet group. 8. Now run the describe-route-tables command using the ID of the VPC returned in the previous step to describe the routes of the VPC's main route table that is implicitly associated with the selected subnet: aws ec2 describe-route-tables --region <region-name> --filters Name=vpc-id,Values=<vpc-id> Name=association.main,Values=true --query 'RouteTables[*].Routes[]' - The command output returns the VPC main route table implicitly associated with the database instance subnet ID. Check the values of the GatewayId and DestinationCidrBlock attributes returned in the output. If the route table contains any entries with the GatewayId value set to igw-xxxxxxxx and the DestinationCidrBlock value set to 0.0.0.0/0, the selected RDS database instance was provisioned inside a public subnet; therefore, it is not running within a logically isolated environment and does not adhere to AWS security best practices.

Automated

Ensure that no public-facing RDS database instances are provisioned in your AWS account, and restrict unauthorized access in order to minimize security risks. When the RDS instance allows unrestricted access (0.0.0.0/0), anyone and anything on the Internet can establish a connection to your database, which can increase the opportunity for malicious activities such as brute force attacks, PostgreSQL injections, or DoS/DDoS attacks.

From Console: 1. Log in to the AWS management console and navigate to the RDS dashboard at https://console.aws.amazon.com/rds/. 2. Under the navigation panel, on the RDS dashboard, click Databases. 3. Select the RDS instance that you want to update. 4. Click Modify from the dashboard top menu. 5. On the Modify DB Instance panel, under the Connectivity section, click on Additional connectivity configuration and update the value for Publicly Accessible to Not publicly accessible to restrict public access. 6. Follow the below steps to update subnet configurations: - Select the Connectivity and security tab, and click the VPC attribute value inside the Networking section. - Select the Details tab from the VPC dashboard's bottom panel and click the Route table configuration attribute value. - On the Route table details page, select the Routes tab from the dashboard's bottom panel and click Edit routes. - On the Edit routes page, update the Destination of Target which is set to igw-xxxxx and click Save routes. 7. On the Modify DB Instance panel, click Continue, and in the Scheduling of modifications section, perform one of the following actions based on your requirements: - Select Apply during the next scheduled maintenance window to apply the changes automatically during the next scheduled maintenance window. - Select Apply immediately to apply the changes right away. With this option, any pending modifications will be asynchronously applied as soon as possible, regardless of the maintenance window setting for this RDS database instance. Note that any changes available in the pending modifications queue are also applied. If any of the pending modifications require downtime, choosing this option can cause unexpected downtime for the application. 8. Repeat steps 3-7 for each RDS instance in the current region. 9. Change the AWS region from the navigation bar to repeat the process for other regions. From Command Line: 1. Run the describe-db-instances command to list all available RDS database identifiers in the selected AWS region: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. The command output should return each database instance identifier. 3. Run the modify-db-instance command to modify the configuration of a selected RDS instance, disabling the Publicly Accessible flag for that instance. This command uses the apply-immediately flag. If you want to avoid any downtime, the --no-apply-immediately flag can be used: aws rds modify-db-instance --region <region-name> --db-instance-identifier <db-instance-name> --no-publicly-accessible --apply-immediately 4. The command output should reveal the PubliclyAccessible configuration under pending values, to be applied at the specified time. 5. Updating the Internet Gateway destination via the AWS CLI is not currently supported. To update information about the Internet Gateway, please use the AWS Console procedure. 6. Repeat steps 1-5 for each RDS instance provisioned in the current region. 7. Change the AWS region by using the --region filter to repeat the process for other regions.

Level 1

2 Storage

2.2 Relational Database Service (RDS)

Amazon RDS offers Multi-AZ deployments that provide enhanced availability and durability for your databases, using synchronous replication to replicate data to a standby instance in a different Availability Zone (AZ). In the event of an infrastructure failure, Amazon RDS automatically fails over to the standby to minimize downtime and ensure business continuity.

From Console: 1. Login to the AWS Management Console and open the RDS dashboard at AWS RDS Console. 2. In the navigation pane, under Databases, select the RDS instance you want to examine. 3. Click the Instance Name to see details, then navigate to the Configuration tab. 4. Under the Availability & Durability section, check the Multi-AZ status. - If Multi-AZ deployment is enabled, it will display Yes. - If it is disabled, the status will display No. 5. Repeat steps 2-4 to verify the Multi-AZ status of other RDS instances in the same region. 6. Change the region from the top of the navigation bar and repeat the audit for other regions. From Command Line: 1. Run the following command to list all RDS instances in the selected AWS region: aws rds describe-db-instances --region <region-name> --query 'DBInstances[*].DBInstanceIdentifier' 2. Run the following command using the instance identifier returned earlier to check the Multi-AZ status: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-name> --query 'DBInstances[*].MultiAZ' - If the output is True, Multi-AZ is enabled. - If the output is False, Multi-AZ is not enabled. 3. Repeat steps 1 and 2 to audit each RDS instance, and change regions to verify in other regions.

Multi-AZ deployments may increase costs due to the additional resources required to maintain a standby instance; however, the benefits of increased availability and reduced risk of downtime outweigh these costs for critical applications.

Manual

Database availability is crucial for maintaining service uptime, particularly for applications that are critical to the business. Implementing Multi-AZ deployments with Amazon RDS ensures that your databases are protected against unplanned outages due to hardware failures, network issues, or other disruptions. This configuration enhances both the availability and durability of your database, making it a highly recommended practice for production environments.

From Console: 1. Login to the AWS Management Console and open the RDS dashboard at AWS RDS Console. 2. In the left navigation pane, click on Databases. 3. Select the database instance that needs Multi-AZ deployment to be enabled. 4. Click the Modify button at the top right. 5. Scroll down to the Availability & Durability section. 6. Under Multi-AZ deployment, select Yes to enable. 7. Review the changes and click Continue. 8. On the Review page, choose Apply immediately to make the change without waiting for the next maintenance window, or Apply during the next scheduled maintenance window. 9. Click Modify DB Instance to apply the changes. From Command Line: 1. Run the following command to modify the RDS instance and enable Multi-AZ: aws rds modify-db-instance --region <region-name> --db-instance-identifier <db-name> --multi-az --apply-immediately 2. Confirm that the Multi-AZ deployment is enabled by running the following command: aws rds describe-db-instances --region <region-name> --db-instance-identifier <db-name> --query 'DBInstances[*].MultiAZ' - The output should return True, indicating that Multi-AZ is enabled. 3. Repeat the procedure for other instances as necessary.

Level 1

2 Storage

2.3 Elastic File System (EFS)

EFS data should be encrypted at rest using AWS KMS (Key Management Service).

EFS file system data is encrypted at rest by default when creating a file system through the Console. However, encryption at rest is not enabled by default when creating a new file system using the AWS CLI, API, or SDKs.

From Console: 1. Login to the AWS Management Console and Navigate to the Elastic File System (EFS) dashboard. 2. Select File Systems from the left navigation panel. 3. Each item on the list has a visible Encrypted field that displays data at rest encryption status. 4. Validate that this field reads Encrypted for all EFS file systems in all AWS regions. From CLI: 1. Run the describe-file-systems command using custom query filters to list the identifiers of all AWS EFS file systems currently available within the selected region: aws efs describe-file-systems --region <region> --output table --query 'FileSystems[*].FileSystemId' 2. The command output should return a table with the requested file system IDs. 3. Run the describe-file-systems command using the ID of the file system that you want to examine as file-system-id and the necessary query filters: aws efs describe-file-systems --region <region> --file-system-id <file-system-id> --query 'FileSystems[*].Encrypted' 4. The command output should return the file system encryption status as true or false. If the returned value is false, the selected AWS EFS file system is not encrypted and if the returned value is true, the selected AWS EFS file system is encrypted.

Automated

Data should be encrypted at rest to reduce the risk of a data breach via direct access to the storage device.

It is important to note that EFS file system data-at-rest encryption must be turned on when creating the file system. If an EFS file system has been created without data-at-rest encryption enabled, then you must create another EFS file system with the correct configuration and transfer the data. Steps to create an EFS file system with data encrypted at rest: From Console: 1. Login to the AWS Management Console and Navigate to the Elastic File System (EFS) dashboard. 2. Select File Systems from the left navigation panel. 3. Click the Create File System button from the dashboard top menu to start the file system setup process. 4. On the Configure file system access configuration page, perform the following actions: - Choose an appropriate VPC from the VPC dropdown list. - Within the Create mount targets section, check the boxes for all of the Availability Zones (AZs) within the selected VPC. These will be your mount targets. - Click Next step to continue. 5. Perform the following on the Configure optional settings page: - Create tags to describe your new file system. - Choose performance mode based on your requirements. - Check the Enable encryption box and choose aws/elasticfilesystem from the Select KMS master key dropdown list to enable encryption for the new file system, using the default master key provided and managed by AWS KMS. - Click Next step to continue. 6. Review the file system configuration details on the review and create page and then click Create File System to create your new AWS EFS file system. 7. Copy the data from the old unencrypted EFS file system onto the newly created encrypted file system. 8. Remove the unencrypted file system as soon as your data migration to the newly created encrypted file system is completed. 9. Change the AWS region from the navigation bar and repeat the entire process for the other AWS regions. From CLI: 1. Run the describe-file-systems command to view the configuration information for the selected unencrypted file system identified in the Audit steps: aws efs describe-file-systems --region <region> --file-system-id <file-system-id> 2. The command output should return the configuration information. 3. To provision a new AWS EFS file system, you need to generate a universally unique identifier (UUID) to create the token required by the create-file-system command. To create the required token, you can use a randomly generated UUID from https://www.uuidgenerator.net. 4. Run the create-file-system command using the unique token created at the previous step: aws efs create-file-system --region <region> --creation-token <uuid> --performance-mode generalPurpose --encrypted 5. The command output should return the new file system configuration metadata. 6. Run the create-mount-target command using the EFS file system ID returned from step 4 as the identifier and the ID of the Availability Zone (AZ) that will represent the mount target: aws efs create-mount-target --region <region> --file-system-id <file-system-id> --subnet-id <subnet-id> 7. The command output should return the new mount target metadata. 8. Now you can mount your file system from an EC2 instance. 9. Copy the data from the old unencrypted EFS file system to the newly created encrypted file system. 10. Remove the unencrypted file system as soon as your data migration to the newly created encrypted file system is completed: aws efs delete-file-system --region <region> --file-system-id <unencrypted-file-system-id> 11. Change the AWS region by updating the --region and repeat the entire process for the other AWS regions.

Level 1

3 Logging

AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you. The recorded information includes the identity of the API caller, the time of the API call, the source IP address of the API caller, the request parameters, and the response elements returned by the AWS service. CloudTrail provides a history of AWS API calls for an account, including API calls made via the Management Console, SDKs, command line tools, and higher-level AWS services (such as CloudFormation).

Not Enabled

Perform the following to determine if CloudTrail is enabled for all regions: From Console: 1. Sign in to the AWS Management Console and open the CloudTrail console at https://console.aws.amazon.com/cloudtrail 2. Click on Trails in the left navigation pane - You will be presented with a list of trails across all regions 3. Ensure that at least one Trail has Yes specified in the Multi-region trail column 4. Click on a trail via the link in the Name column 5. Ensure Logging is set to ON 6. Ensure Multi-region trail is set to Yes 7. In the section Management Events, ensure that API activity set to ALL From Command Line: 1. List all trails: aws cloudtrail describe-trails 2. Ensure IsMultiRegionTrail is set to true: aws cloudtrail get-trail-status --name <trail-name> 3. Ensure IsLogging is set to true: aws cloudtrail get-event-selectors --trail-name <trail-name> 4. Ensure there is at least one fieldSelector for a trail that equals Management: - This should NOT output any results for Field: readOnly. If either true or false is returned, one of the checkboxes (read or write) is not selected. Example of correct output: TrailARN: <your_trail_ARN>, AdvancedEventSelectors: [ { Name: Management events selector, FieldSelectors: [ { Field: eventCategory, Equals: [ Management ]

S3 lifecycle features can be used to manage the accumulation and management of logs over time. See the following AWS resource for more information on these features: 1. https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lifecycle-mgmt.html

Manual

The AWS API call history produced by CloudTrail enables security analysis, resource change tracking, and compliance auditing. Additionally, - ensuring that a multi-region trail exists will help detect unexpected activity occurring in otherwise unused regions - ensuring that a multi-region trail exists will ensure that Global Service Logging is enabled for a trail by default to capture recordings of events generated on AWS global services - for a multi-region trail, ensuring that management events are configured for all types of Read/Writes ensures the recording of management operations that are performed on all resources in an AWS account

Perform the following to enable global (Multi-region) CloudTrail logging: From Console: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/cloudtrail. 2. Click on Trails in the left navigation pane. 3. Click Get Started Now if it is presented, then: - Click Add new trail. - Enter a trail name in the Trail name box. - A trail created in the console is a multi-region trail by default. - Specify an S3 bucket name in the S3 bucket box. - Specify the AWS KMS alias under the Log file SSE-KMS encryption section, or create a new key. - Click Next. 4. Ensure the Management events check box is selected. 5. Ensure both Read and Write are checked under API activity. 6. Click Next. 7. Review your trail settings and click Create trail. From Command Line: Create a multi-region trail: aws cloudtrail create-trail --name <trail-name> --bucket-name <s3-bucket-for-cloudtrail> --is-multi-region-trail Enable multi-region on an existing trail: aws cloudtrail update-trail --name <trail-name> --is-multi-region-trail Note: Creating a CloudTrail trail via the CLI without providing any overriding options configures all read and write Management Events to be logged by default.

Level 2

3 Logging

CloudTrail log file validation creates a digitally signed digest file containing a hash of each log that CloudTrail writes to S3. These digest files can be used to determine whether a log file was changed, deleted, or remained unchanged after CloudTrail delivered the log. It is recommended that file validation be enabled for all CloudTrails.

Not Enabled

Perform the following on each trail to determine if log file validation is enabled: From Console: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/cloudtrail. 2. Click on Trails in the left navigation pane. 3. For every trail: - Click on a trail via the link in the Name column. - Under the General details section, ensure Log file validation is set to Enabled. From Command Line: List all trails: aws cloudtrail describe-trails Ensure LogFileValidationEnabled is set to true for each trail.

Automated

Enabling log file validation will provide additional integrity checks for CloudTrail logs.

Perform the following to enable log file validation on a given trail: From Console: 1. Sign in to the AWS Management Console and open the IAM console at https://console.aws.amazon.com/cloudtrail. 2. Click on Trails in the left navigation pane. 3. Click on the target trail. 4. Within the General details section, click edit. 5. Under Advanced settings, check the enable box under Log file validation. 6. Click Save changes. From Command Line: Enable log file validation on a trail: aws cloudtrail update-trail --name <trail_name> --enable-log-file-validation Note that periodic validation of logs using these digests can be carried out by running the following command: aws cloudtrail validate-logs --trail-arn <trail_arn> --start-time <start_time> --end-time <end_time>

Level 2

3 Logging

AWS Config is a web service that performs configuration management of supported AWS resources within your account and delivers log files to you. The recorded information includes the configuration items (AWS resources), relationships between configuration items (AWS resources), and any configuration changes between resources. It is recommended that AWS Config be enabled in all regions.

Process to evaluate AWS Config configuration per region: From Console: 1. Sign in to the AWS Management Console and open the AWS Config console at https://console.aws.amazon.com/config/. 1. On the top right of the console select the target region. 1. If a Config Recorder is enabled in this region, you should navigate to the Settings page from the navigation menu on the left-hand side. If a Config Recorder is not yet enabled in this region, proceed to the remediation steps. 1. Ensure Record all resources supported in this region is checked. 1. Ensure Include global resources (e.g., AWS IAM resources) is checked, unless it is enabled in another region (this is only required in one region). 1. Ensure the correct S3 bucket has been defined. 1. Ensure the correct SNS topic has been defined. 1. Repeat steps 2 to 7 for each region. From Command Line: 1. Run this command to show all AWS Config Recorders and their properties: aws configservice describe-configuration-recorders 2. Evaluate the output to ensure that all recorders have a recordingGroup object which includes allSupported: true. Additionally, ensure that at least one recorder has includeGlobalResourceTypes: true. Note: There is one more parameter, ResourceTypes, in the recordingGroup object. We don't need to check it, as whenever we set allSupported to true, AWS enforces the resource types to be empty (ResourceTypes: []). Sample output: { ConfigurationRecorders: [ { recordingGroup: { allSupported: true, resourceTypes: [], includeGlobalResourceTypes: true }, roleARN: arn:aws:iam::<AWS_Account_ID>:role/service-role/<config-role-name>, name: default } ] } 3. Run this command to show the status for all AWS Config Recorders: aws configservice describe-configuration-recorder-status 4. In the output, find recorders with name key matching the recorders that were evaluated in step 2. Ensure that they include recording: true and lastStatus: SUCCESS.

Enabling AWS Config in all regions provides comprehensive visibility into resource configurations, enhancing security and compliance monitoring. However, this may incur additional costs and require proper configuration management.

Automated

The AWS configuration item history captured by AWS Config enables security analysis, resource change tracking, and compliance auditing.

To implement AWS Config configuration: From Console: 1. Select the region you want to focus on in the top right of the console. 2. Click Services. 3. Click Config. 4. If a Config Recorder is enabled in this region, navigate to the Settings page from the navigation menu on the left-hand side. If a Config Recorder is not yet enabled in this region, select Get Started. 5. Select Record all resources supported in this region. 6. Choose to include global resources (IAM resources). 7. Specify an S3 bucket in the same account or in another managed AWS account. 8. Create an SNS Topic from the same AWS account or another managed AWS account. From Command Line: 1. Ensure there is an appropriate S3 bucket, SNS topic, and IAM role per the AWS Config Service prerequisites. 2. Run this command to create a new configuration recorder: aws configservice put-configuration-recorder --configuration-recorder name=<config-recorder-name>,roleARN=arn:aws:iam::<account-id>:role/<iam-role> --recording-group allSupported=true,includeGlobalResourceTypes=true 3. Create a delivery channel configuration file locally which specifies the channel attributes, populated from the prerequisites set up previously: { name: <delivery-channel-name>, s3BucketName: <bucket-name>, snsTopicARN: arn:aws:sns:<region>:<account-id>:<sns-topic>, configSnapshotDeliveryProperties: { deliveryFrequency: Twelve_Hours } } 4. Run this command to create a new delivery channel, referencing the json configuration file made in the previous step: aws configservice put-delivery-channel --delivery-channel file://<delivery-channel-file>.json 5. Start the configuration recorder by running the following command: aws configservice start-configuration-recorder --configuration-recorder-name <config-recorder-name>

Level 1

3 Logging

Server access logging generates a log that contains access records for each request made to your S3 bucket. An access log record contains details about the request, such as the request type, the resources specified in the request worked, and the time and date the request was processed. It is recommended that server access logging be enabled on the CloudTrail S3 bucket.

Logging is disabled.

Perform the following ensure that the CloudTrail S3 bucket has access logging is enabled: From Console: 1. Go to the Amazon CloudTrail console at https://console.aws.amazon.com/cloudtrail/home. 2. In the API activity history pane on the left, click Trails. 3. In the Trails pane, note the bucket names in the S3 bucket column. 4. Sign in to the AWS Management Console and open the S3 console at https://console.aws.amazon.com/s3. 5. Under All Buckets click on a target S3 bucket. 6. Click on Properties in the top right of the console. 7. Under Bucket: <bucket-name>, click Logging. 8. Ensure Enabled is checked. From Command Line: 1. Get the name of the S3 bucket that CloudTrail is logging to: aws cloudtrail describe-trails --query 'trailList[*].S3BucketName' 2. Ensure logging is enabled on the bucket: aws s3api get-bucket-logging --bucket <s3-bucket-for-cloudtrail> Ensure the command does not return an empty output. Sample output for a bucket with logging enabled: { LoggingEnabled: { TargetPrefix: <log-file-prefix>, TargetBucket: <logging-bucket> } }

Manual

By enabling server access logging on target S3 buckets, it is possible to capture all events that may affect objects within any target bucket. Configuring the logs to be placed in a separate bucket allows access to log information that can be useful in security and incident response workflows.

Perform the following to enable server access logging: From Console: 1. Sign in to the AWS Management Console and open the S3 console at https://console.aws.amazon.com/s3. 2. Under All Buckets click on the target S3 bucket. 3. Click on Properties in the top right of the console. 4. Under Bucket: <bucket-name>, click Logging. 5. Configure bucket logging: - Check the Enabled box. - Select a Target Bucket from the list. - Enter a Target Prefix. 6. Click Save. From Command Line: 1. Get the name of the S3 bucket that CloudTrail is logging to: aws cloudtrail describe-trails --region <region-name> --query trailList[*].S3BucketName 2. Copy and add the target bucket name at <bucket-name>, the prefix for the log file at <log-file-prefix>, and optionally add an email address in the following template, then save it as <file-name>.json: { LoggingEnabled: { TargetBucket: <bucket-name>, TargetPrefix: <log-file-prefix>, TargetGrants: [ { Grantee: { Type: AmazonCustomerByEmail, EmailAddress: <email-address> }, Permission: FULL_CONTROL } ] } } 3. Run the put-bucket-logging command with bucket name and <file-name>.json as input; for more information, refer to put-bucket-logging: aws s3api put-bucket-logging --bucket <bucket-name> --bucket-logging-status file://<file-name>.json

Level 2

3 Logging

AWS CloudTrail is a web service that records AWS API calls for an account and makes those logs available to users and resources in accordance with IAM policies. AWS Key Management Service (KMS) is a managed service that helps create and control the encryption keys used to encrypt account data, and uses Hardware Security Modules (HSMs) to protect the security of encryption keys. CloudTrail logs can be configured to leverage server side encryption (SSE) and KMS customer-created master keys (CMK) to further protect CloudTrail logs. It is recommended that CloudTrail be configured to use SSE-KMS.

Perform the following to determine if CloudTrail is configured to use SSE-KMS: From Console: 1. Sign in to the AWS Management Console and open the CloudTrail console at https://console.aws.amazon.com/cloudtrail. 2. In the left navigation pane, choose Trails. 3. Select a trail. 4. In the General details section, select Edit to edit the trail configuration. 5. Ensure the box at Log file SSE-KMS encryption is checked and that a valid AWS KMS alias of a KMS key is entered in the respective text box. From Command Line: 1. Run the following command: aws cloudtrail describe-trails 2. For each trail listed, SSE-KMS is enabled if the trail has a KmsKeyId property defined.

Customer-created keys incur an additional cost. See https://aws.amazon.com/kms/pricing/ for more information.

Automated

Configuring CloudTrail to use SSE-KMS provides additional confidentiality controls on log data, as a given user must have S3 read permission on the corresponding log bucket and must be granted decrypt permission by the CMK policy.

Perform the following to configure CloudTrail to use SSE-KMS: From Console: 1. Sign in to the AWS Management Console and open the CloudTrail console at https://console.aws.amazon.com/cloudtrail. 2. In the left navigation pane, choose Trails. 3. Click on a trail. 4. Under the S3 section, click the edit button (pencil icon). 5. Click Advanced. 6. Select an existing CMK from the KMS key Id drop-down menu. - Note: Ensure the CMK is located in the same region as the S3 bucket. - Note: You will need to apply a KMS key policy on the selected CMK in order for CloudTrail, as a service, to encrypt and decrypt log files using the CMK provided. View the AWS documentation for editing the selected CMK Key policy. 7. Click Save. 8. You will see a notification message stating that you need to have decryption permissions on the specified KMS key to decrypt log files. 9. Click Yes. From Command Line: Run the following command to specify a KMS key ID to use with a trail: aws cloudtrail update-trail --name <trail-name> --kms-id <cloudtrail-kms-key> Run the following command to attach a key policy to a specified KMS key: aws kms put-key-policy --key-id <cloudtrail-kms-key> --policy <cloudtrail-kms-key-policy>

Three statements that need to be added to the CMK policy: 1. Enable CloudTrail to describe CMK properties: <pre class=programlisting style=font-style: normal;>{ Sid: Allow CloudTrail access, Effect: Allow, Principal: { Service: cloudtrail.amazonaws.com }, Action: kms:DescribeKey, Resource: * } 2. Granting encrypt permissions: <pre class=programlisting style=font-style: normal;>{ Sid: Allow CloudTrail to encrypt logs, Effect: Allow, Principal: { Service: cloudtrail.amazonaws.com }, Action: kms:GenerateDataKey*, Resource: *, Condition: { StringLike: { kms:EncryptionContext:aws:cloudtrail:arn: [ arn:aws:cloudtrail:*:aws-account-id:trail/* ] } } } 3. Granting decrypt permissions: <pre class=programlisting style=font-style: normal;>{ Sid: Enable CloudTrail log decrypt permissions, Effect: Allow, Principal: { AWS: arn:aws:iam::aws-account-id:user/username }, Action: kms:Decrypt, Resource: *, Condition: { Null: { kms:EncryptionContext:aws:cloudtrail:arn: false } } }

Level 2

3 Logging

AWS Key Management Service (KMS) allows customers to rotate the backing key, which is key material stored within the KMS that is tied to the key ID of the customer-created customer master key (CMK). The backing key is used to perform cryptographic operations such as encryption and decryption. Automated key rotation currently retains all prior backing keys so that decryption of encrypted data can occur transparently. It is recommended that CMK key rotation be enabled for symmetric keys. Key rotation cannot be enabled for any asymmetric CMK.

From Console: 1. Sign in to the AWS Management Console and open the KMS console at: https://console.aws.amazon.com/kms. 2. In the left navigation pane, click Customer-managed keys. 3. Select a customer-managed CMK where Key spec = SYMMETRIC_DEFAULT. 4. Select the Key rotation tab. 5. Ensure the Automatically rotate this KMS key every year box is checked. 6. Repeat steps 3–5 for all customer-managed CMKs where Key spec = SYMMETRIC_DEFAULT. From Command Line: 1. Run the following command to get a list of all keys and their associated KeyIds: aws kms list-keys 2. For each key, note the KeyId and run the following command: describe-key --key-id <kms-key-id> 3. If the response contains KeySpec = SYMMETRIC_DEFAULT, run the following command: aws kms get-key-rotation-status --key-id <kms-key-id> 4. Ensure KeyRotationEnabled is set to true. 5. Repeat steps 2–4 for all remaining CMKs.

Creation, management, and storage of CMKs may require additional time from an administrator.

Automated

Rotating encryption keys helps reduce the potential impact of a compromised key, as data encrypted with a new key cannot be accessed with a previous key that may have been exposed. Keys should be rotated every year or upon an event that could result in the compromise of that key.

From Console: 1. Sign in to the AWS Management Console and open the KMS console at: https://console.aws.amazon.com/kms. 2. In the left navigation pane, click Customer-managed keys. 3. Select a key with Key spec = SYMMETRIC_DEFAULT that does not have automatic rotation enabled. 4. Select the Key rotation tab. 5. Check the Automatically rotate this KMS key every year box. 6. Click Save. 7. Repeat steps 3–6 for all customer-managed CMKs that do not have automatic rotation enabled. From Command Line: 1. Run the following command to enable key rotation: aws kms enable-key-rotation --key-id <kms-key-id>

Level 2

3 Logging

VPC Flow Logs is a feature that enables you to capture information about the IP traffic going to and from network interfaces in your VPC. After you've created a flow log, you can view and retrieve its data in Amazon CloudWatch Logs. It is recommended that VPC Flow Logs be enabled for packet Rejects for VPCs.

Perform the following to determine if VPC Flow logs are enabled: From Console: 1. Sign into the management console. 2. Select Services, then select VPC. 3. In the left navigation pane, select Your VPCs. 4. Select a VPC. 5. In the right pane, select the Flow Logs tab. 6. Ensure a Log Flow exists that has Active in the Status column. From Command Line: 1. Run the describe-vpcs command (OSX/Linux/UNIX) to list the VPC networks available in the current AWS region: aws ec2 describe-vpcs --region <region> --query Vpcs[].VpcId 2. The command output returns the VpcId of VPCs available in the selected region. 3. Run the describe-flow-logs command (OSX/Linux/UNIX) using the VPC ID to determine if the selected virtual network has the Flow Logs feature enabled: aws ec2 describe-flow-logs --filter Name=resource-id,Values=<vpc-id> - If there are no Flow Logs created for the selected VPC, the command output will return an empty list []. 4. Repeat step 3 for other VPCs in the same region. 5. Change the region by updating --region, and repeat steps 1-4 for each region.

By default, CloudWatch Logs will store logs indefinitely unless a specific retention period is defined for the log group. When choosing the number of days to retain, keep in mind that the average time it takes for an organization to realize they have been breached is 210 days (at the time of this writing). Since additional time is required to research a breach, a minimum retention policy of 365 days allows for detection and investigation. You may also wish to archive the logs to a cheaper storage service rather than simply deleting them. See the following AWS resource to manage CloudWatch Logs retention periods: 1. https://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/SettingLogRetention.html

Automated

VPC Flow Logs provide visibility into network traffic that traverses the VPC and can be used to detect anomalous traffic or gain insights during security workflows.

Perform the following to enable VPC Flow Logs: From Console: 1. Sign into the management console. 2. Select Services, then select VPC. 3. In the left navigation pane, select Your VPCs. 4. Select a VPC. 5. In the right pane, select the Flow Logs tab. 6. If no Flow Log exists, click Create Flow Log. 7. For Filter, select Reject. 8. Enter a Role and Destination Log Group. 9. Click Create Log Flow. 10. Click on CloudWatch Logs Group. Note: Setting the filter to Reject will dramatically reduce the accumulation of logging data for this recommendation and provide sufficient information for the purposes of breach detection, research, and remediation. However, during periods of least privilege security group engineering, setting the filter to All can be very helpful in discovering existing traffic flows required for the proper operation of an already running environment. From Command Line: 1. Create a policy document, name it role_policy_document.json, and paste the following content: { Version: 2012-10-17, Statement: [ { Sid: test, Effect: Allow, Principal: { Service: ec2.amazonaws.com }, Action: sts:AssumeRole } ] } 2. Create another policy document, name it iam_policy.json, and paste the following content: { Version: 2012-10-17, Statement: [ { Effect: Allow, Action:[ logs:CreateLogGroup, logs:CreateLogStream, logs:DescribeLogGroups, logs:DescribeLogStreams, logs:PutLogEvents, logs:GetLogEvents, logs:FilterLogEvents ], Resource: * } ] } 3. Run the following command to create an IAM role: aws iam create-role --role-name <aws-support-iam-role> --assume-role-policy-document file://<file-path>role_policy_document.json 4. Run the following command to create an IAM policy: aws iam create-policy --policy-name <iam-policy-name> --policy-document file://<file-path>iam-policy.json 5. Run the attach-group-policy command, using the IAM policy ARN returned from the previous step to attach the policy to the IAM role: aws iam attach-group-policy --policy-arn arn:aws:iam::<aws-account-id>:policy/<iam-policy-name> --group-name <group-name> - If the command succeeds, no output is returned. 6. Run the describe-vpcs command to get a list of VPCs in the selected region: aws ec2 describe-vpcs --region <region> - The command output should return a list of VPCs in the selected region. 7. Run the create-flow-logs command to create a flow log for a VPC: aws ec2 create-flow-logs --resource-type VPC --resource-ids <vpc-id> --traffic-type REJECT --log-group-name <log-group-name> --deliver-logs-permission-arn <iam-role-arn> 8. Repeat step 7 for other VPCs in the selected region. 9. Change the region by updating --region, and repeat the remediation procedure for each region.

Level 2

3 Logging

S3 object-level API operations, such as GetObject, DeleteObject, and PutObject, are referred to as data events. By default, CloudTrail trails do not log data events, so it is recommended to enable object-level logging for S3 buckets.

From Console: 1. Login to the AWS Management Console and navigate to the CloudTrail dashboard at https://console.aws.amazon.com/cloudtrail/. 2. In the left panel, click Trails, and then click the name of the trail that you want to examine. 3. Review General details. 4. Confirm that Multi-region trail is set to Yes. 5. Scroll down to Data events and confirm the configuration: - If advanced event selectors is being used, it should read: Data Events: S3 Log selector template Log all events - If basic event selectors is being used, it should read: Data events: S3 Bucket Name: All current and future S3 buckets Write: Enabled 6. Repeat steps 2-5 to verify that each trail has multi-region enabled and is configured to log data events. If a trail does not have multi-region enabled and data event logging configured, refer to the remediation steps. From Command Line: 1. Run the list-trails command to list all trails: aws cloudtrail list-trails 2. The command output will be a list of trails: TrailARN: arn:aws:cloudtrail:<region>:<account#>:trail/<trail-name>, Name: <trail-name>, HomeRegion: <region> 3. Run the get-trail command to determine whether a trail is a multi-region trail: aws cloudtrail get-trail --name <trail-name> --region <region-name> 4. The command output should include: IsMultiRegionTrail: true. 5. Run the get-event-selectors command, using the Name of the trail and the region returned in step 2, to determine if data event logging is configured: aws cloudtrail get-event-selectors --region <home-region> --trail-name <trail-name> --query EventSelectors[*].DataResources[] 6. The command output should be an array that includes the S3 bucket defined for data event logging: Type: AWS::S3::Object, Values: [ arn:aws:s3 7. If the get-event-selectors command returns an empty array, data events are not included in the trail's logging configuration; therefore, object-level API operations performed on S3 buckets within your AWS account are not being recorded. 8. Repeat steps 1-7 to verify that each trail has multi-region enabled and is configured to log data events. If a trail does not have multi-region enabled and data event logging configured, refer to the remediation steps.

Enabling logging for these object-level events may significantly increase the number of events logged and may incur additional costs.

Automated

Enabling object-level logging will help you meet data compliance requirements within your organization, perform comprehensive security analyses, monitor specific patterns of user behavior in your AWS account, or take immediate actions on any object-level API activity within your S3 buckets using Amazon CloudWatch Events.

From Console: 1. Login to the AWS Management Console and navigate to the S3 dashboard at https://console.aws.amazon.com/s3/. 2. In the left navigation panel, click buckets, and then click the name of the S3 bucket you want to examine. 3. Click the Properties tab to see the bucket configuration in detail. 4. In the AWS CloudTrail data events section, select the trail name for recording activity. You can choose an existing trail or create a new one by clicking the Configure in CloudTrail button or navigating to the CloudTrail console. 5. Once the trail is selected, select the Data Events check box. 6. Select S3 from the Data event type drop-down. 7. Select Log all events from the Log selector template drop-down. 8. Repeat steps 2-7 to enable object-level logging of write events for other S3 buckets. From Command Line: 1. To enable object-level data events logging for S3 buckets within your AWS account, run the put-event-selectors command using the name of the trail that you want to reconfigure as identifier: aws cloudtrail put-event-selectors --region <region-name> --trail-name <trail-name> --event-selectors '[{ ReadWriteType: WriteOnly, IncludeManagementEvents:true, DataResources: [{ Type: AWS::S3::Object, Values: [arn:aws:s3:::<s3-bucket-name>/] }] }]' 2. The command output will be object-level event trail configuration. 3. If you want to enable it for all buckets at once, change the Values parameter to [arn:aws:s3] in the previous command. 4. Repeat step 1 for each s3 bucket to update object-level logging of write events. 5. Change the AWS region by updating the --region command parameter, and perform the process for the other regions.

Level 2

3 Logging

S3 object-level API operations, such as GetObject, DeleteObject, and PutObject, are referred to as data events. By default, CloudTrail trails do not log data events, so it is recommended to enable object-level logging for S3 buckets.

From Console: 1. Login to the AWS Management Console and navigate to the CloudTrail dashboard at https://console.aws.amazon.com/cloudtrail/. 2. In the left panel, click Trails, and then click the name of the trail that you want to examine. 3. Review General details. 4. Confirm that Multi-region trail is set to Yes 5. Scroll down to Data events 5. Scroll down to Data events and confirm the configuration: - If advanced event selectors is being used, it should read: Data Events: S3 Log selector template Log all events - If basic event selectors is being used, it should read: Data events: S3 Bucket Name: All current and future S3 buckets Read: Enabled 6. Repeat steps 2-5 to verify that each trail has multi-region enabled and is configured to log data events. If a trail does not have multi-region enabled and data event logging configured, refer to the remediation steps. From Command Line: 1. Run the describe-trails command to list all trail names: aws cloudtrail describe-trails --region <region-name> --output table --query trailList[*].Name 2. The command output will be table of the trail names. 3. Run the get-event-selectors command using the name of a trail returned at the previous step and custom query filters to determine if data event logging is configured: aws cloudtrail get-event-selectors --region <region-name> --trail-name <trail-name> --query EventSelectors[*].DataResources[] 4. The command output should be an array that includes the S3 bucket defined for data event logging. 5. If the get-event-selectors command returns an empty array, data events are not included in the trail's logging configuration; therefore, object-level API operations performed on S3 buckets within your AWS account are not being recorded. 6. Repeat steps 1-5 to verify the configuration of each trail. 7. Change the AWS region by updating the --region command parameter, and perform the audit process for other regions.

Enabling logging for these object-level events may significantly increase the number of events logged and may incur additional costs.

Automated

Enabling object-level logging will help you meet data compliance requirements within your organization, perform comprehensive security analyses, monitor specific patterns of user behavior in your AWS account, or take immediate actions on any object-level API activity within your S3 buckets using Amazon CloudWatch Events.

From Console: 1. Login to the AWS Management Console and navigate to S3 dashboard at https://console.aws.amazon.com/s3/. 2. In the left navigation panel, click buckets and then click the name of the S3 bucket that you want to examine. 3. Click the Properties tab to see the bucket configuration in detail. 4. In the AWS Cloud Trail data events section, select the trail name for recording activity. You can choose an existing trail or create a new one by clicking the Configure in CloudTrail button or navigating to the CloudTrail console. 5. Once the trail is selected, select the Data Events check box. 6. Select S3 from the Data event type drop-down. 7. Select Log all events from the Log selector template drop-down. 8. Repeat steps 2-7 to enable object-level logging of read events for other S3 buckets. From Command Line: 1. To enable object-level data events logging for S3 buckets within your AWS account, run the put-event-selectors command using the name of the trail that you want to reconfigure as identifier: aws cloudtrail put-event-selectors --region <region-name> --trail-name <trail-name> --event-selectors '[{ ReadWriteType: ReadOnly, IncludeManagementEvents:true, DataResources: [{ Type: AWS::S3::Object, Values: [arn:aws:s3:::<s3-bucket-name>/] }] }]' 2. The command output will be object-level event trail configuration. 3. If you want to enable it for all buckets at once, change the Values parameter to [arn:aws:s3] in the previous command. 4. Repeat step 1 for each s3 bucket to update object-level logging of read events. 5. Change the AWS region by updating the --region command parameter, and perform the process for the other regions.

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for unauthorized API calls.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.errorCode =*UnauthorizedOperation) || ($.errorCode =AccessDenied*) && ($.sourceIPAddress!=delivery.logs.amazonaws.com) && ($.eventName!=HeadBucket) }, 4. Note the <unauthorized-api-calls-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <unauthorized-api-calls-metric> captured in step 4: aws cloudwatch describe-alarms --query MetricAlarms[?MetricName == <unauthorized-api-calls-metric>] 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

This alert may be triggered by normal read-only console activities that attempt to opportunistically gather optional information but gracefully fail if they lack the necessary permissions. If an excessive number of alerts are generated, then an organization may wish to consider adding read access to the limited IAM user permissions solely to reduce the number of alerts. In some cases, doing this may allow users to actually view some areas of the system; any additional access granted should be reviewed for alignment with the original limited IAM user intent.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring unauthorized API calls will help reduce the time it takes to detect malicious activity and can alert you to potential security incidents.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for unauthorized API calls and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <unauthorized-api-calls-metric> --metric-transformations metricName=unauthorized_api_calls_metric,metricNamespace=CISBenchmark,metricValue=1 --filter-pattern { ($.errorCode =*UnauthorizedOperation) || ($.errorCode =AccessDenied*) && ($.sourceIPAddress!=delivery.logs.amazonaws.com) && ($.eventName!=HeadBucket) } Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name unauthorized_api_calls_alarm --metric-name unauthorized_api_calls_metric --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace CISBenchmark --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for console logins that are not protected by multi-factor authentication (MFA).

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: aws cloudtrail get-trail-status --name <trail-name> - ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = ConsoleLogin) && ($.additionalEventData.MFAUsed != Yes) } Or, to reduce false positives in case Single Sign-On (SSO) is used in the organization: filterPattern: { ($.eventName = ConsoleLogin) && ($.additionalEventData.MFAUsed != Yes) && ($.userIdentity.type = IAMUser) && ($.responseElements.ConsoleLogin = Success) } 4. Note the <no-mfa-console-signin-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <no-mfa-console-signin-metric> captured in step 4. aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName== <no-mfa-console-signin-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring for single-factor console logins will increase visibility into accounts that are not protected by MFA. These type of accounts are more susceptible to compromise and unauthorized access.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for AWS Management Console sign-ins without MFA and uses the <trail-log-group-name> taken from audit step 1. aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name `<no-mfa-console-signin-metric>` --metric-transformations metricName= `<no-mfa-console-signin-metric>`,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = ConsoleLogin) && ($.additionalEventData.MFAUsed != Yes) }' Or, to reduce false positives in case Single Sign-On (SSO) is used in the organization: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name `<no-mfa-console-signin-metric>` --metric-transformations metricName= `<no-mfa-console-signin-metric>`,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = ConsoleLogin) && ($.additionalEventData.MFAUsed != Yes) && ($.userIdentity.type = IAMUser) && ($.responseElements.ConsoleLogin = Success) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name `<no-mfa-console-signin-alarm>` --metric-name `<no-mfa-console-signin-metric>` --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored Filter pattern set to { ($.eventName = ConsoleLogin) && ($.additionalEventData.MFAUsed != Yes) && ($.userIdentity.type = IAMUser) && ($.responseElements.ConsoleLogin = Success}: - reduces false alarms raised when a user logs in via SSO

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for 'root' login attempts to detect unauthorized use or attempts to use the root account.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { $.userIdentity.type = Root && $.userIdentity.invokedBy NOT EXISTS && $.eventType != AwsServiceEvent } 4. Note the <root-usage-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <root-usage-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<root-usage-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring 'root' account logins will provide visibility into the use of a fully privileged account and the opportunity to reduce its usage.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for 'root' account usage and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name `<trail-log-group-name>` --filter-name `<root-usage-metric>` --metric-transformations metricName= `<root-usage-metric>` ,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ $.userIdentity.type = Root && $.userIdentity.invokedBy NOT EXISTS && $.eventType != AwsServiceEvent }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name `<root-usage-alarm>` --metric-name `<root-usage-metric>` --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns_topic_arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for changes made to Identity and Access Management (IAM) policies.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: {($.eventName=DeleteGroupPolicy)||($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)} 4. Note the <iam-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <iam-change-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<iam-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Monitoring these changes may result in a number of false positives, especially in larger environments. This alert may require more tuning than others to eliminate some of those erroneous notifications.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to IAM policies will help ensure authentication and authorization controls remain intact.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for IAM policy changes and the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name `<trail-log-group-name>` --filter-name `<iam-changes-metric>` --metric-transformations metricName= `<iam-changes-metric>`,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{($.eventName=DeleteGroupPolicy)||($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)}' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name `<iam-changes-alarm>` --metric-name `<iam-changes-metric>` --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be used to detect changes to CloudTrail's configurations.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = CreateTrail) || ($.eventName = UpdateTrail) || ($.eventName = DeleteTrail) || ($.eventName = StartLogging) || ($.eventName = StopLogging) } 4. Note the <cloudtrail-cfg-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <cloudtrail-cfg-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<cloudtrail-cfg-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Ensuring that changes to CloudTrail configurations are monitored enhances security by maintaining the integrity of logging mechanisms. Automated monitoring can provide real-time alerts; however, it may require additional setup and resources to configure and manage these alerts effectively. These steps can be performed manually within a company's existing SIEM platform in cases where CloudTrail logs are monitored outside of the AWS monitoring tools in CloudWatch.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to CloudTrail's configuration will help ensure sustained visibility into the activities performed in the AWS account.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for CloudTrail configuration changes and the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <cloudtrail-cfg-changes-metric> --metric-transformations metricName=<cloudtrail-cfg-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = CreateTrail) || ($.eventName = UpdateTrail) || ($.eventName = DeleteTrail) || ($.eventName = StartLogging) || ($.eventName = StopLogging) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <cloudtrail-cfg-changes-alarm> --metric-name <cloudtrail-cfg-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for failed console authentication attempts.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = ConsoleLogin) && ($.errorMessage = Failed authentication) } 4. Note the <console-signin-failure-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <console-signin-failure-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<console-signin-failure-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Monitoring for these failures may generate a large number of alerts, especially in larger environments.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring failed console logins may decrease the lead time to detect an attempt to brute-force a credential, which may provide an indicator, such as the source IP address, that can be used in other event correlations.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for AWS management Console login failures and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <console-signin-failure-metric> --metric-transformations metricName=<console-signin-failure-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = ConsoleLogin) && ($.errorMessage = Failed authentication) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <console-signin-failure-alarm> --metric-name <console-signin-failure-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for customer-created CMKs that have changed state to disabled or are scheduled for deletion.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: {($.eventSource = kms.amazonaws.com) && (($.eventName=DisableKey)||($.eventName=ScheduleKeyDeletion)) } 4. Note the <disable-or-delete-cmk-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <disable-or-delete-cmk-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<disable-or-delete-cmk-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Creation, storage, and management of CMK may require additional labor compared to the use of AWS-managed keys.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Data encrypted with disabled or deleted keys will no longer be accessible. Changes in the state of a CMK should be monitored to ensure that the change is intentional.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for CMKs that have been disabled or scheduled for deletion and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <disable-or-delete-cmk-changes-metric> --metric-transformations metricName=<disable-or-delete-cmk-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{($.eventSource = kms.amazonaws.com) && (($.eventName=DisableKey)||($.eventName=ScheduleKeyDeletion)) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <disable-or-delete-cmk-changes-alarm> --metric-name <disable-or-delete-cmk-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for changes to S3 bucket policies.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventSource = s3.amazonaws.com) && (($.eventName = PutBucketAcl) || ($.eventName = PutBucketPolicy) || ($.eventName = PutBucketCors) || ($.eventName = PutBucketLifecycle) || ($.eventName = PutBucketReplication) || ($.eventName = DeleteBucketPolicy) || ($.eventName = DeleteBucketCors) || ($.eventName = DeleteBucketLifecycle) || ($.eventName = DeleteBucketReplication)) } 4. Note the <s3-bucket-policy-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <s3-bucket-policy-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<s3-bucket-policy-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to S3 bucket policies may reduce the time it takes to detect and correct permissive policies on sensitive S3 buckets.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for changes to S3 bucket policies and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <s3-bucket-policy-changes-metric> --metric-transformations metricName=<s3-bucket-policy-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventSource = s3.amazonaws.com) && (($.eventName = PutBucketAcl) || ($.eventName = PutBucketPolicy) || ($.eventName = PutBucketCors) || ($.eventName = PutBucketLifecycle) || ($.eventName = PutBucketReplication) || ($.eventName = DeleteBucketPolicy) || ($.eventName = DeleteBucketCors) || ($.eventName = DeleteBucketLifecycle) || ($.eventName = DeleteBucketReplication)) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <s3-bucket-policy-changes-alarm> --metric-name <s3-bucket-policy-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for detecting changes to AWS Config's configurations.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventSource = config.amazonaws.com) && (($.eventName=StopConfigurationRecorder)||($.eventName=DeleteDeliveryChannel)||($.eventName=PutDeliveryChannel)||($.eventName=PutConfigurationRecorder)) } 4. Note the <aws-config-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <aws-config-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<aws-config-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to the AWS Config configuration will help ensure sustained visibility of the configuration items within the AWS account.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for AWS Configuration changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <aws-config-changes-metric> --metric-transformations metricName=<aws-config-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventSource = config.amazonaws.com) && (($.eventName=StopConfigurationRecorder)||($.eventName=DeleteDeliveryChannel)||($.eventName=PutDeliveryChannel)||($.eventName=PutConfigurationRecorder)) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <aws-config-changes-alarm> --metric-name <aws-config-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. Security groups are stateful packet filters that control ingress and egress traffic within a VPC. It is recommended that a metric filter and alarm be established to detect changes to security groups.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = AuthorizeSecurityGroupIngress) || ($.eventName = AuthorizeSecurityGroupEgress) || ($.eventName = RevokeSecurityGroupIngress) || ($.eventName = RevokeSecurityGroupEgress) || ($.eventName = CreateSecurityGroup) || ($.eventName = DeleteSecurityGroup) || ($.eventName = ModifySecurityGroupRules) } 4. Note the <security-group-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <security-group-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query MetricAlarms[?MetricName==<security-group-changes-metric>] 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

This may require additional 'tuning' to eliminate false positives and filter out expected activity so that anomalies are easier to detect.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to security groups will help ensure that resources and services are not unintentionally exposed.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for security groups changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <security-group-changes-metric> --metric-transformations metricName=<security-group-changes-metric>,metricNamespace=CISBenchmark,metricValue=1 --filter-pattern { ($.eventName = AuthorizeSecurityGroupIngress) || ($.eventName = AuthorizeSecurityGroupEgress) || ($.eventName = RevokeSecurityGroupIngress) || ($.eventName = RevokeSecurityGroupEgress) || ($.eventName = CreateSecurityGroup) || ($.eventName = DeleteSecurityGroup) || ($.eventName = ModifySecurityGroupRules) } Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <security-group-changes-alarm> --metric-name <security-group-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace CISBenchmark --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored AWS has recently introduced a new API, ModifySecurityGroupRules, which modifies the rules of a security group.

Level 2

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. NACLs are used as a stateless packet filter to control ingress and egress traffic for subnets within a VPC. It is recommended that a metric filter and alarm be established for any changes made to NACLs.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = CreateNetworkAcl) || ($.eventName = CreateNetworkAclEntry) || ($.eventName = DeleteNetworkAcl) || ($.eventName = DeleteNetworkAclEntry) || ($.eventName = ReplaceNetworkAclEntry) || ($.eventName = ReplaceNetworkAclAssociation) } 4. Note the <nacl-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <nacl-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<nacl-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to NACLs will help ensure that AWS resources and services are not unintentionally exposed.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for NACL changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <nacl-changes-metric> --metric-transformations metricName=<nacl-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = CreateNetworkAcl) || ($.eventName = CreateNetworkAclEntry) || ($.eventName = DeleteNetworkAcl) || ($.eventName = DeleteNetworkAclEntry) || ($.eventName = ReplaceNetworkAclEntry) || ($.eventName = ReplaceNetworkAclAssociation) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <nacl-changes-alarm> --metric-name <nacl-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. Network gateways are required to send and receive traffic to a destination outside of a VPC. It is recommended that a metric filter and alarm be established for changes to network gateways.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = CreateCustomerGateway) || ($.eventName = DeleteCustomerGateway) || ($.eventName = AttachInternetGateway) || ($.eventName = CreateInternetGateway) || ($.eventName = DeleteInternetGateway) || ($.eventName = DetachInternetGateway) } 4. Note the <network-gw-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <network-gw-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<network-gw-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id> 8. Ensure automated monitoring is enabled: aws cloudwatch put-metric-alarm --alarm-name NetworkGatewayChanges --metric-name GatewayChanges --namespace AWS/EC2 --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --alarm-actions <sns-topic-arn>

Monitoring changes to network gateways helps detect unauthorized modifications that could compromise network security. Implementing automated monitoring and alerts can improve incident response times, but it may require additional configuration and maintenance efforts.

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to network gateways will help ensure that all ingress/egress traffic traverses the VPC border via a controlled path.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for network gateways changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <network-gw-changes-metric> --metric-transformations metricName=<network-gw-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = CreateCustomerGateway) || ($.eventName = DeleteCustomerGateway) || ($.eventName = AttachInternetGateway) || ($.eventName = CreateInternetGateway) || ($.eventName = DeleteInternetGateway) || ($.eventName = DetachInternetGateway) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <network-gw-changes-alarm> --metric-name <network-gw-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn> 5. Implement logging and alerting mechanisms: aws sns create-topic --name NetworkGatewayChangesAlerts ```` aws sns subscribe --topic-arn <sns-topic-arn> --protocol email --notification-endpoint <email-address> aws cloudwatch put-metric-alarm --alarm-name NetworkGatewayChangesAlarm --metric-name GatewayChanges --namespace AWS/EC2 --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --alarm-actions <sns-topic-arn> ```

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. Routing tables are used to route network traffic between subnets and to network gateways. It is recommended that a metric filter and alarm be established for changes to route tables.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: {($.eventSource = ec2.amazonaws.com) && ($.eventName = CreateRoute) || ($.eventName = CreateRouteTable) || ($.eventName = ReplaceRoute) || ($.eventName = ReplaceRouteTableAssociation) || ($.eventName = DeleteRouteTable) || ($.eventName = DeleteRoute) || ($.eventName = DisassociateRouteTable) } 4. Note the <route-table-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <route-table-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<route-table-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring changes to route tables will help ensure that all VPC traffic flows through the expected path and prevent any accidental or intentional modifications that may lead to uncontrolled network traffic. An alarm should be triggered every time an AWS API call is performed to create, replace, delete, or disassociate a route table.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for route table changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-pattern '{ ($.eventName = CreateRoute) || ($.eventName = CreateRouteTable) || ($.eventName = ReplaceRoute) || ($.eventName = ReplaceRouteTableAssociation) || ($.eventName = DeleteRouteTable) || ($.eventName = DeleteRoute) || ($.eventName = DisassociateRouteTable) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <route-table-changes-alarm> --metric-name <route-table-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is possible to have more than one VPC within an account; additionally, it is also possible to create a peer connection between two VPCs, enabling network traffic to route between them. It is recommended that a metric filter and alarm be established for changes made to VPCs.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventName = CreateVpc) || ($.eventName = DeleteVpc) || ($.eventName = ModifyVpcAttribute) || ($.eventName = AcceptVpcPeeringConnection) || ($.eventName = CreateVpcPeeringConnection) || ($.eventName = DeleteVpcPeeringConnection) || ($.eventName = RejectVpcPeeringConnection) || ($.eventName = AttachClassicLinkVpc) || ($.eventName = DetachClassicLinkVpc) || ($.eventName = DisableVpcClassicLink) || ($.eventName = EnableVpcClassicLink) } 4. Note the <vpc-changes-metric> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <vpc-changes-metric> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<vpc-changes-metric>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. VPCs in AWS are logically isolated virtual networks that can be used to launch AWS resources. Monitoring changes to VPC configurations will help ensure that VPC traffic flow is not negatively impacted. Changes to VPCs can affect network accessibility from the public internet and additionally impact VPC traffic flow to and from the resources launched in the VPC.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for VPC changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <vpc-changes-metric> --metric-transformations metricName=<vpc-changes-metric>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventName = CreateVpc) || ($.eventName = DeleteVpc) || ($.eventName = ModifyVpcAttribute) || ($.eventName = AcceptVpcPeeringConnection) || ($.eventName = CreateVpcPeeringConnection) || ($.eventName = DeleteVpcPeeringConnection) || ($.eventName = RejectVpcPeeringConnection) || ($.eventName = AttachClassicLinkVpc) || ($.eventName = DetachClassicLinkVpc) || ($.eventName = DisableVpcClassicLink) || ($.eventName = EnableVpcClassicLink) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <vpc-changes-alarm> --metric-name <vpc-changes-metric> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 1

4 Monitoring

Real-time monitoring of API calls can be achieved by directing CloudTrail Logs to CloudWatch Logs or an external Security Information and Event Management (SIEM) environment, and establishing corresponding metric filters and alarms. It is recommended that a metric filter and alarm be established for changes made to AWS Organizations in the master AWS account.

If you are using CloudTrail trails and CloudWatch, perform the following to ensure that there is at least one active multi-region CloudTrail trail with the prescribed metric filters and alarms configured: 1. Identify the log group name that is configured for use with the active multi-region CloudTrail trail: - List all CloudTrail trails: aws cloudtrail describe-trails - Identify multi-region CloudTrail trails: Trails with IsMultiRegionTrail set to true - Note the value associated with Name:<trail-name> - Note the <trail-log-group-name> within the value associated with CloudWatchLogsLogGroupArn - Example: arn:aws:logs:<region>:<account-id>:log-group:<trail-log-group-name>:* - Ensure the identified multi-region CloudTrail trail is active: - aws cloudtrail get-trail-status --name <trail-name> - Ensure IsLogging is set to TRUE - Ensure the identified multi-region CloudTrail trail captures all management events: - aws cloudtrail get-event-selectors --trail-name <trail-name> - Ensure there is at least one event selector for a trail with IncludeManagementEvents set to true and ReadWriteType set to All 2. Get a list of all associated metric filters for the <trail-log-group-name> captured in step 1: aws logs describe-metric-filters --log-group-name <trail-log-group-name> 3. Ensure the output from the above command contains the following: filterPattern: { ($.eventSource = organizations.amazonaws.com) && (($.eventName = AcceptHandshake) || ($.eventName = AttachPolicy) || ($.eventName = CreateAccount) || ($.eventName = CreateOrganizationalUnit) || ($.eventName = CreatePolicy) || ($.eventName = DeclineHandshake) || ($.eventName = DeleteOrganization) || ($.eventName = DeleteOrganizationalUnit) || ($.eventName = DeletePolicy) || ($.eventName = DetachPolicy) || ($.eventName = DisablePolicyType) || ($.eventName = EnablePolicyType) || ($.eventName = InviteAccountToOrganization) || ($.eventName = LeaveOrganization) || ($.eventName = MoveAccount) || ($.eventName = RemoveAccountFromOrganization) || ($.eventName = UpdatePolicy) || ($.eventName = UpdateOrganizationalUnit)) } 4. Note the <organizations-changes> value associated with the filterPattern from step 3. 5. Get a list of CloudWatch alarms, and filter on the <organizations-changes> captured in step 4: aws cloudwatch describe-alarms --query 'MetricAlarms[?MetricName==<organizations-changes>]' 6. Note the AlarmActions value; this will provide the SNS topic ARN value. 7. Ensure there is at least one active subscriber to the SNS topic: aws sns list-subscriptions-by-topic --topic-arn <sns-topic-arn> - At least one subscription should have SubscriptionArn with a valid AWS ARN. - Example of valid SubscriptionArn: arn:aws:sns:<region>:<account-id>:<sns-topic-name>:<subscription-id>

Manual

CloudWatch is an AWS native service that allows you to observe and monitor resources and applications. CloudTrail logs can also be sent to an external Security Information and Event Management (SIEM) environment for monitoring and alerting. Monitoring AWS Organizations changes can help you prevent unwanted, accidental, or intentional modifications that may lead to unauthorized access or other security breaches. This monitoring technique helps ensure that any unexpected changes made within your AWS Organizations can be investigated and that any unwanted changes can be rolled back.

If you are using CloudTrail trails and CloudWatch, perform the following steps to set up the metric filter, alarm, SNS topic, and subscription: 1. Create a metric filter based on the provided filter pattern that checks for AWS Organizations changes and uses the <trail-log-group-name> taken from audit step 1: aws logs put-metric-filter --log-group-name <trail-log-group-name> --filter-name <organizations-changes> --metric-transformations metricName=<organizations-changes>,metricNamespace='CISBenchmark',metricValue=1 --filter-pattern '{ ($.eventSource = organizations.amazonaws.com) && (($.eventName = AcceptHandshake) || ($.eventName = AttachPolicy) || ($.eventName = CreateAccount) || ($.eventName = CreateOrganizationalUnit) || ($.eventName = CreatePolicy) || ($.eventName = DeclineHandshake) || ($.eventName = DeleteOrganization) || ($.eventName = DeleteOrganizationalUnit) || ($.eventName = DeletePolicy) || ($.eventName = DetachPolicy) || ($.eventName = DisablePolicyType) || ($.eventName = EnablePolicyType) || ($.eventName = InviteAccountToOrganization) || ($.eventName = LeaveOrganization) || ($.eventName = MoveAccount) || ($.eventName = RemoveAccountFromOrganization) || ($.eventName = UpdatePolicy) || ($.eventName = UpdateOrganizationalUnit)) }' Note: You can choose your own metricName and metricNamespace strings. Using the same metricNamespace for all Foundations Benchmark metrics will group them together. 2. Create an SNS topic that the alarm will notify: aws sns create-topic --name <sns-topic-name> Note: You can execute this command once and then reuse the same topic for all monitoring alarms. Note: Capture the TopicArn that is displayed when creating the SNS topic in step 2. 3. Create an SNS subscription for the topic created in step 2: aws sns subscribe --topic-arn <sns-topic-arn> --protocol <sns-protocol> --notification-endpoint <sns-subscription-endpoints> Note: You can execute this command once and then reuse the same subscription for all monitoring alarms. 4. Create an alarm that is associated with the CloudWatch Logs metric filter created in step 1 and the SNS topic created in step 2: aws cloudwatch put-metric-alarm --alarm-name <organizations-changes> --metric-name <organizations-changes> --statistic Sum --period 300 --threshold 1 --comparison-operator GreaterThanOrEqualToThreshold --evaluation-periods 1 --namespace 'CISBenchmark' --alarm-actions <sns-topic-arn>

Configuring a log metric filter and alarm on a multi-region (global) CloudTrail trail: - ensures that activities from all regions (both used and unused) are monitored - ensures that activities on all supported global services are monitored - ensures that all management events across all regions are monitored

Level 2

4 Monitoring

Security Hub collects security data from various AWS accounts, services, and supported third-party partner products, helping you analyze your security trends and identify the highest-priority security issues. When you enable Security Hub, it begins to consume, aggregate, organize, and prioritize findings from the AWS services that you have enabled, such as Amazon GuardDuty, Amazon Inspector, and Amazon Macie. You can also enable integrations with AWS partner security products.

Follow this process to evaluate AWS Security Hub configuration per region: From Console: 1. Sign in to the AWS Management Console and open the AWS Security Hub console at https://console.aws.amazon.com/securityhub/. 2. On the top right of the console, select the target Region. 3. If the Security Hub > Summary page is displayed, then Security Hub is set up for the selected region. 4. If presented with Setup Security Hub or Get Started With Security Hub, refer to the remediation steps. 5. Repeat steps 2 to 4 for each region. From Command Line: Run the following command to verify the Security Hub status: aws securityhub describe-hub This will list the Security Hub status by region. Check for a 'SubscribedAt' value. Example output: { HubArn: <security-hub-arn>, SubscribedAt: 2022-08-19T17:06:42.398Z, AutoEnableControls: true } An error will be returned if Security Hub is not enabled. Example error: An error occurred (InvalidAccessException) when calling the DescribeHub operation: Account <Account ID> is not subscribed to AWS Security Hub

It is recommended that AWS Security Hub be enabled in all regions. AWS Security Hub requires that AWS Config be enabled.

Automated

AWS Security Hub provides you with a comprehensive view of your security state in AWS and helps you check your environment against security industry standards and best practices, enabling you to quickly assess the security posture across your AWS accounts.

To grant the permissions required to enable Security Hub, attach the Security Hub managed policy AWSSecurityHubFullAccess to an IAM user, group, or role. Enabling Security Hub: From Console: 1. Use the credentials of the IAM identity to sign in to the Security Hub console. 2. When you open the Security Hub console for the first time, choose Go to Security Hub. 3. The Security standards section on the welcome page lists supported security standards. Check the box for a standard to enable it. 3. Choose Enable Security Hub. From Command Line: 1. Run the enable-security-hub command, including --enable-default-standards to enable the default standards: aws securityhub enable-security-hub --enable-default-standards 2. To enable Security Hub without the default standards, include --no-enable-default-standards: aws securityhub enable-security-hub --no-enable-default-standards

Level 1

5 Networking

5.1 Elastic Compute Cloud (EC2)

Elastic Compute Cloud (EC2) supports encryption at rest when using the Elastic Block Store (EBS) service. While disabled by default, forcing encryption at EBS volume creation is supported.

From Console: 1. Login to the AWS Management Console and open the Amazon EC2 console using https://console.aws.amazon.com/ec2/. 2. Under Settings, click EBS encryption. 3. Verify Always encrypt new EBS volumes displays Enabled. 4. Repeat for each region in use. Note: EBS volume encryption is configured per region. From Command Line: 1. Run the following command: aws --region <region> ec2 get-ebs-encryption-by-default 2. Verify that EbsEncryptionByDefault: true is displayed. 3. Repeat for each region in use. Note: EBS volume encryption is configured per region.

Losing access to or removing the KMS key used by the EBS volumes will result in the inability to access the volumes.

Automated

Encrypting data at rest reduces the likelihood of unintentional exposure and can nullify the impact of disclosure if the encryption remains unbroken.

From Console: 1. Login to the AWS Management Console and open the Amazon EC2 console using https://console.aws.amazon.com/ec2/. 2. Under Account attributes, click EBS encryption. 3. Click Manage. 4. Check the Enable box. 5. Click Update EBS encryption. 6. Repeat for each region in which EBS volume encryption is not enabled by default. Note: EBS volume encryption is configured per region. From Command Line: 1. Run the following command: aws --region <region> ec2 enable-ebs-encryption-by-default 2. Verify that EbsEncryptionByDefault: true is displayed. 3. Repeat for each region in which EBS volume encryption is not enabled by default. Note: EBS volume encryption is configured per region.

Default EBS volume encryption only applies to newly created EBS volumes; existing EBS volumes are not converted automatically.

Level 1

5 Networking

5.1 Elastic Compute Cloud (EC2)

Common Internet File System (CIFS) is a network file-sharing protocol that allows systems to share files over a network. However, unrestricted CIFS access can expose your data to unauthorized users, leading to potential security risks. It is important to restrict CIFS access to only trusted networks and users to prevent unauthorized access and data breaches.

From Console: 1. Login to the AWS Management Console. 2. Navigate to the EC2 Dashboard and select the Security Groups section under Network & Security. 3. Identify the security groups associated with instances or resources that may be using CIFS. 4. Review the inbound rules of each security group to check for rules that allow unrestricted access on port 445 (the port used by CIFS). - Specifically, look for inbound rules that allow access from 0.0.0.0/0 or ::/0 on port 445. 5. Document any instances where unrestricted access is allowed and verify whether it is necessary for the specific use case. From Command Line: 1. Run the following command to list all security groups and identify those associated with CIFS: aws ec2 describe-security-groups --region <region-name> --query 'SecurityGroups[*].GroupId' 2. Check for any inbound rules that allow unrestricted access on port 445 using the following command: aws ec2 describe-security-groups --region <region-name> --group-ids <security-group-id> --query 'SecurityGroups[*].IpPermissions[?ToPort==`445`].{CIDR:IpRanges[*].CidrIp,Port:ToPort}' - Look for 0.0.0.0/0 or ::/0 in the output, which indicates unrestricted access. 3. Repeat the audit for other regions and security groups as necessary.

Restricting CIFS access may require additional configuration and management effort. However, the benefits of enhanced security and reduced risk of unauthorized access to sensitive data far outweigh the potential challenges.

Automated

Allowing unrestricted CIFS access can lead to significant security vulnerabilities, as it may allow unauthorized users to access sensitive files and data. By restricting CIFS access to known and trusted networks, you can minimize the risk of unauthorized access and protect sensitive data from exposure to potential attackers. Implementing proper network access controls and permissions is essential for maintaining the security and integrity of your file-sharing systems.

From Console: 1. Login to the AWS Management Console. 2. Navigate to the EC2 Dashboard and select the Security Groups section under Network & Security. 3. Identify the security group that allows unrestricted ingress on port 445. 4. Select the security group and click the Edit Inbound Rules button. 5. Locate the rule allowing unrestricted access on port 445 (typically listed as 0.0.0.0/0 or ::/0). 6. Modify the rule to restrict access to specific IP ranges or trusted networks only. 7. Save the changes to the security group. From Command Line: 1. Run the following command to remove or modify the unrestricted rule for CIFS access: aws ec2 revoke-security-group-ingress --region <region-name> --group-id <security-group-id> --protocol tcp --port 445 --cidr 0.0.0.0/0 - Optionally, run the authorise-security-group-ingress command to create a new rule, specifying a trusted CIDR range instead of 0.0.0.0/0. 2. Confirm the changes by describing the security group again and ensuring the unrestricted access rule has been removed or appropriately restricted: aws ec2 describe-security-groups --region <region-name> --group-ids <security-group-id> --query 'SecurityGroups[*].IpPermissions[?ToPort==`445`].{CIDR:IpRanges[*].CidrIp,Port:ToPort}' 3. Repeat the remediation for other security groups and regions as necessary.

Level 1

5 Networking

The Network Access Control List (NACL) function provides stateless filtering of ingress and egress network traffic to AWS resources. It is recommended that no NACL allows unrestricted ingress access to remote server administration ports, such as SSH on port 22 and RDP on port 3389, using either the TCP (6), UDP (17), or ALL (-1) protocols.

From Console: Perform the following steps to determine if the account is configured as prescribed: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Network ACLs. 3. For each network ACL, perform the following: - Select the network ACL. - Click the Inbound Rules tab. - Ensure that no rule exists which has a port range that includes port 22 or 3389, uses the protocols TCP (6), UDP (17), or ALL (-1), or other remote server administration ports for your environment, has a Source of 0.0.0.0/0, and shows ALLOW. Note: A port value of ALL or a port range such as 0-3389 includes port 22, 3389, and potentially other remote server administration ports.

Automated

Public access to remote server administration ports, such as 22 (when used for SSH, not SFTP) and 3389, increases the attack surface of resources and unnecessarily raises the risk of resource compromise.

From Console: Perform the following steps to remediate a network ACL: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Network ACLs. 3. For each network ACL that needs remediation, perform the following: - Select the network ACL. - Click the Inbound Rules tab. - Click Edit inbound rules. - Either A) update the Source field to a range other than 0.0.0.0/0, or B) click Delete to remove the offending inbound rule. - Click Save.

Level 1

5 Networking

Security groups provide stateful filtering of ingress and egress network traffic to AWS resources. It is recommended that no security group allows unrestricted ingress access to remote server administration ports, such as SSH on port 22 and RDP on port 3389, using either the TCP (6), UDP (17), or ALL (-1) protocols.

Perform the following to determine if the account is configured as prescribed: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Security Groups. 3. For each security group, perform the following: - Select the security group. - Click the Inbound Rules tab. - Ensure that no rule exists which has a port range including port 22 or 3389, uses the protocols TCP (6), UDP (17), or ALL (-1), or other remote server administration ports for your environment, and has a Source of 0.0.0.0/0. Note: A port value of ALL or a port range such as 0-3389 includes port 22, 3389, and potentially other remote server administration ports.

When updating an existing environment, ensure that administrators have access to remote server administration ports through another mechanism before removing access by deleting the 0.0.0.0/0 inbound rule.

Automated

Public access to remote server administration ports, such as 22 (when used for SSH, not SFTP) and 3389, increases the attack surface of resources and unnecessarily raises the risk of resource compromise.

Perform the following to implement the prescribed state: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Security Groups. 3. For each security group, perform the following: - Select the security group. - Click the Inbound Rules tab. - Click the Edit inbound rules button. - Identify the rules to be edited or removed. - Either A) update the Source field to a range other than 0.0.0.0/0, or B) click Delete to remove the offending inbound rule. - Click Save rules.

Level 1

5 Networking

Security groups provide stateful filtering of ingress and egress network traffic to AWS resources. It is recommended that no security group allows unrestricted ingress access to remote server administration ports, such as SSH on port 22 and RDP on port 3389.

Perform the following to determine if the account is configured as prescribed: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Security Groups. 3. For each security group, perform the following: - Select the security group. - Click the Inbound Rules tab. - Ensure that no rule exists which has a port range including port 22, 3389, or other remote server administration ports for your environment, and has a Source of ::/0. Note: A port value of ALL or a port range such as 0-3389 includes port 22, 3389, and potentially other remote server administration ports.

When updating an existing environment, ensure that administrators have access to remote server administration ports through another mechanism before removing access by deleting the ::/0 inbound rule.

Automated

Public access to remote server administration ports, such as 22 (when used for SSH, not SFTP) and 3389, increases attack surface of resources and unnecessarily raises the risk of resource compromise.

Perform the following to implement the prescribed state: 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. In the left pane, click Security Groups. 3. For each security group, perform the following: - Select the security group. - Click the Inbound Rules tab. - Click the Edit inbound rules button. - Identify the rules to be edited or removed. - Either A) update the Source field to a range other than ::/0, or B) Click Delete to remove the offending inbound rule. - Click Save rules.

Level 2

5 Networking

A VPC comes with a default security group whose initial settings deny all inbound traffic, allow all outbound traffic, and allow all traffic between instances assigned to the security group. If a security group is not specified when an instance is launched, it is automatically assigned to this default security group. Security groups provide stateful filtering of ingress/egress network traffic to AWS resources. It is recommended that the default security group restrict all traffic, both inbound and outbound. The default VPC in every region should have its default security group updated to comply with the following: - No inbound rules. - No outbound rules. Any newly created VPCs will automatically contain a default security group that will need remediation to comply with this recommendation. Note: When implementing this recommendation, VPC flow logging is invaluable in determining the least privilege port access required by systems to work properly, as it can log all packet acceptances and rejections occurring under the current security groups. This dramatically reduces the primary barrier to least privilege engineering by discovering the minimum ports required by systems in the environment. Even if the VPC flow logging recommendation in this benchmark is not adopted as a permanent security measure, it should be used during any period of discovery and engineering for least privileged security groups.

Perform the following to determine if the account is configured as prescribed: Security Group State 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. Repeat the following steps for all VPCs, including the default VPC in each AWS region: 3. In the left pane, click Security Groups. 4. For each default security group, perform the following: - Select the default security group. - Click the Inbound Rules tab and ensure no rules exist. - Click the Outbound Rules tab and ensure no rules exist. Security Group Members 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. Repeat the following steps for all default groups in all VPCs, including the default VPC in each AWS region: 3. In the left pane, click Security Groups. 4. Copy the ID of the default security group. 5. Change to the EC2 Management Console at https://console.aws.amazon.com/ec2/v2/home. 6. In the filter column type Security Group ID : <security-group-id-from-step-4>.

Implementing this recommendation in an existing VPC that contains operating resources requires extremely careful migration planning, as the default security groups are likely enabling many ports that are unknown. Enabling VPC flow logging (for accepted connections) in an existing environment that is known to be breach-free will reveal the current pattern of ports being used for each instance to communicate successfully. The migration process should include: - Analyzing VPC flow logs to understand current traffic patterns. - Creating least privilege security groups based on the analyzed data. - Testing the new security group rules in a staging environment before applying them to production.

Automated

Configuring all VPC default security groups to restrict all traffic will encourage the development of least privilege security groups and promote the mindful placement of AWS resources into security groups, which will, in turn, reduce the exposure of those resources.

Perform the following to implement the prescribed state: Security Group Members 1. Identify AWS resources that exist within the default security group. 2. Create a set of least-privilege security groups for those resources. 3. Place the resources in those security groups, removing the resources noted in step 1 from the default security group. Security Group State 1. Login to the AWS VPC Console at https://console.aws.amazon.com/vpc/home. 2. Repeat the following steps for all VPCs, including the default VPC in each AWS region: 3. In the left pane, click Security Groups. 4. For each default security group, perform the following: - Select the default security group. - Click the Inbound Rules tab. - Remove any inbound rules. - Click the Outbound Rules tab. - Remove any Outbound rules. Recommended IAM groups allow you to edit the name field. After remediating default group rules for all VPCs in all regions, edit this field to add text similar to DO NOT USE. DO NOT ADD RULES.

Level 2

5 Networking

Once a VPC peering connection is established, routing tables must be updated to enable any connections between the peered VPCs. These routes can be as specific as desired, even allowing for the peering of a VPC to only a single host on the other side of the connection.

Review the routing tables of peered VPCs to determine whether they route all subnets of each VPC and whether this is necessary to accomplish the intended purposes of peering the VPCs. From Command Line: 1. List all the route tables from a VPC and check if the GatewayId is pointing to a <peering-connection-id> (e.g., pcx-1a2b3c4d) and if the DestinationCidrBlock is as specific as desired: aws ec2 describe-route-tables --filter Name=vpc-id,Values=<vpc-id> --query RouteTables[*].{RouteTableId:RouteTableId, VpcId:VpcId, Routes:Routes, AssociatedSubnets:Associations[*].SubnetId}

Manual

Being highly selective in peering routing tables is a very effective way to minimize the impact of a breach, as resources outside of these routes are inaccessible to the peered VPC.

Remove and add route table entries to ensure that the least number of subnets or hosts required to accomplish the purpose of peering are routable. From Command Line: 1. For each <route-table-id> that contains routes that are non-compliant with your routing policy (granting more access than desired), delete the non-compliant route: aws ec2 delete-route --route-table-id <route-table-id> --destination-cidr-block <non-compliant-destination-cidr> 2. Create a new compliant route: aws ec2 create-route --route-table-id <route-table-id> --destination-cidr-block <compliant-destination-cidr> --vpc-peering-connection-id <peering-connection-id>

If an organization has an AWS Transit Gateway implemented in its VPC architecture, it should look to apply the recommendation above for a least access routing architecture at the AWS Transit Gateway level, in combination with what must be implemented at the standard VPC route table. More specifically, to route traffic between two or more VPCs via a Transit Gateway, VPCs must have an attachment to a Transit Gateway route table as well as a route. Therefore, to avoid routing traffic between VPCs, an attachment to the Transit Gateway route table should only be added where there is an intention to route traffic between the VPCs. As Transit Gateways are capable of hosting multiple route tables, it is possible to group VPCs by attaching them to a common route table.

Level 1

5 Networking

When enabling the Metadata Service on AWS EC2 instances, users have the option of using either Instance Metadata Service Version 1 (IMDSv1; a request/response method) or Instance Metadata Service Version 2 (IMDSv2; a session-oriented method).

From Console: 1. Sign in to the AWS Management Console and navigate to the EC2 dashboard at https://console.aws.amazon.com/ec2/. 2. In the left navigation panel, under the INSTANCES section, choose Instances. 3. Select the EC2 instance that you want to examine. 4. Check the IMDSv2 status, and ensure that it is set to Required. From Command Line: 1. Run the describe-instances command using appropriate filters to list the IDs of all existing EC2 instances currently available in the selected region: aws ec2 describe-instances --region <region-name> --output table --query Reservations[*].Instances[*].InstanceId 2. The command output should return a table with the requested instance IDs. 3. Run the describe-instances command using the instance ID returned in the previous step and apply custom filtering to determine whether the selected instance is using IMDSv2: aws ec2 describe-instances --region <region-name> --instance-ids <instance-id> --query Reservations[*].Instances[*].MetadataOptions --output table 4. Ensure that for all EC2 instances, HttpTokens is set to required and State is set to applied. 5. Repeat steps 3 and 4 to verify the other EC2 instances provisioned within the current region. 6. Repeat steps 1–5 to perform the audit process for other AWS regions.

Automated

Instance metadata is data about your instance that you can use to configure or manage the running instance. Instance metadata is divided into categories, such as host name, events, and security groups. When enabling the Metadata Service on AWS EC2 instances, users have the option of using either Instance Metadata Service Version 1 (IMDSv1; a request/response method) or Instance Metadata Service Version 2 (IMDSv2; a session-oriented method). With IMDSv2, every request is now protected by session authentication. A session begins and ends a series of requests that software running on an EC2 instance uses to access the locally stored EC2 instance metadata and credentials. Allowing Version 1 of the service may open EC2 instances to Server-Side Request Forgery (SSRF) attacks, so Amazon recommends utilizing Version 2 for better instance security.

From Console: 1. Sign in to the AWS Management Console and navigate to the EC2 dashboard at https://console.aws.amazon.com/ec2/. 2. In the left navigation panel, under the INSTANCES section, choose Instances. 3. Select the EC2 instance that you want to examine. 4. Choose Actions > Instance Settings > Modify instance metadata options. 5. Set Instance metadata service to Enable. 6. Set IMDSv2 to Required. 7. Repeat steps 1-6 to perform the remediation process for other EC2 instances in all applicable AWS region(s). From Command Line: 1. Run the describe-instances command, applying the appropriate filters to list the IDs of all existing EC2 instances currently available in the selected region: aws ec2 describe-instances --region <region-name> --output table --query Reservations[*].Instances[*].InstanceId 2. The command output should return a table with the requested instance IDs. 3. Run the modify-instance-metadata-options command with an instance ID obtained from the previous step to update the Instance Metadata Version: aws ec2 modify-instance-metadata-options --instance-id <instance-id> --http-tokens required --region <region-name> 4. Repeat steps 1-3 to perform the remediation process for other EC2 instances in the same AWS region. 5. Change the region by updating --region and repeat the process for other regions.