IAM Principals Should Not Have IAM Inline Policies Rule
This rule states that IAM principals should not have IAM inline policies allowing decryption actions on all KMS keys.
| Rule | IAM principals should not have IAM inline policies that allow decryption actions on all KMS keys |
| Framework | AWS Foundational Security Best Practices |
| Severity | ✔ Medium |
Rule Description:
IAM principals should not have IAM inline policies that allow decryption actions on all KMS keys. This rule is in place to ensure the proper security measures are implemented for AWS KMS (Key Management Service) keys, and prevent unauthorized decryption access to sensitive data.
Reasoning:
Allowing IAM principals to have decryption actions on all KMS keys can lead to potential security vulnerabilities. If an attacker gains access to an IAM principal with such permissions, they could decrypt and access any data encrypted using those KMS keys, potentially exposing sensitive information. By following this best practice, you can minimize the risk of unauthorized access to decrypted data.
Troubleshooting Steps:
If you are experiencing issues related to IAM principals having IAM inline policies that allow decryption actions on all KMS keys, follow these troubleshooting steps:
- 1.
Identify the affected IAM principal: Determine which IAM principal is assigned the problematic IAM inline policy that allows decryption actions on all KMS keys. This could be a user, group, or role that needs to be reviewed and modified.
- 2.
Review the IAM inline policy: Analyze the content of the IAM inline policy associated with the IAM principal. Look for any explicit or wildcard permissions related to the "kms:Decrypt" action on all KMS keys.
- 3.
Determine the right level of access: Assess the actual requirements for the IAM principal in terms of KMS key decryption. Consider whether the IAM principal needs this level of access for all KMS keys or if a more limited scope is sufficient.
- 4.
Modify the IAM inline policy: Update the IAM inline policy to remove the permission for decryption actions on all KMS keys. Instead, grant specific permission to decrypt only the necessary KMS keys.
Remediation Steps:
To remediate the IAM inline policy and restrict decryption actions on KMS keys, follow these steps:
- 1.
Identify the IAM principal: Determine the IAM principal associated with the problematic IAM inline policy that grants decryption actions on all KMS keys.
- 2.
Access the IAM Management Console: Log in to the AWS Management Console and navigate to the IAM service.
- 3.
Modify the IAM inline policy: Locate the IAM principal (user, group, or role) and click on it to access its details.
- 4.
Edit the inline policy: Within the IAM principal details, find the inline policy that grants decryption actions on all KMS keys. Click on the "Edit" button to modify the policy.
- 5.
Update the policy: Remove any permissions related to the "kms:Decrypt" action on all KMS keys. Instead, consider specifying individual KMS keys or a limited group of keys that the IAM principal requires access to.
- 6.
Save the changes: After making the necessary modifications to the IAM inline policy, click on "Review policy" to ensure the changes are correct. Then, save the policy.
- 7.
Test the updated policy: Once saved, verify that the IAM principal no longer has decryption actions on all KMS keys. Test the IAM principal's access to verify it can only decrypt the intended KMS keys.
By following these remediation steps, you can ensure that IAM principals do not have overly permissive inline policies for decryption actions on all KMS keys, actively mitigating potential security risks.