Rule: KMS Key Decryption Restricted in IAM Inline Policy
This rule ensures that KMS key decryption is restricted in IAM inline policy.
| Rule | KMS key decryption should be restricted in IAM inline policy |
| Framework | HIPAA |
| Severity | ✔ Medium |
Description
This rule ensures that Key Management Service (KMS) key decryption actions are restricted in the inline IAM policy for HIPAA compliance. By restricting key decryption, unauthorized access and potential data breaches can be mitigated, safeguarding sensitive data protected by the KMS key.
Policy Details
Policy Statement
A policy statement needs to be added to the inline IAM policy in order to restrict KMS key decryption actions. The policy statement should deny the key decryption action for all entities not explicitly granted permission.
Policy Example
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "RestrictKMSDecryption",
"Effect": "Deny",
"Action": "kms:Decrypt",
"Resource": "*"
}
]
}
The policy example above denies the
kms:DecryptTroubleshooting
If any issues arise while implementing this policy, follow these troubleshooting steps:
- 1.
Permission errors: Ensure that you have the necessary permissions to modify the IAM policies for the relevant entities. Verify that you are editing an inline IAM policy and not a managed policy.
- 2.
Policy conflict: Check if there are any conflicting policies that override or contradict the intended restriction. Review other IAM policies that apply to the same entities and resource. Ensure that there are no conflicting
statements that may grant decryption access.Allow - 3.
Syntax errors: Double-check the syntax of the policy statement. Verify that there are no typos or missing characters. Incorrect formatting can cause the policy to be ineffective or cause unintended permissions.
Remediation
To remediate this issue and restrict KMS key decryption, follow these steps:
- 1.
Identify the inline IAM policy attached to the relevant entities (users, roles, or groups) that require restricted key decryption access.
- 2.
Edit the inline IAM policy and add the following policy statement at the appropriate location (inside the "Statement" array):
{ "Sid": "RestrictKMSDecryption", "Effect": "Deny", "Action": "kms:Decrypt", "Resource": "*" }This policy statement denies the
action on all resources.kms:Decrypt - 3.
Save the updated IAM policy.
- 4.
Test the restricted key decryption access by attempting to decrypt a KMS-encrypted resource using an entity covered by the policy. Verify that the decryption request is denied.
- 5.
If the remediation does not work as expected or there are any issues, refer to the troubleshooting steps above to identify and resolve any problems.
Conclusion
By implementing this policy to restrict KMS key decryption in the inline IAM policy, you enhance the security and compliance of your infrastructure, specifically for HIPAA requirements. This policy ensures that only authorized entities can perform decryption actions, reducing the risk of unauthorized data access and potential breaches.