AWS Certified Security – Specialty — Question 416

A team is using AWS Secrets Manager to store an application database password. Only a limited number of IAM principals within the account can have access to the secret. The principals who require access to the secret change frequently. A security engineer must create a solution that maximizes flexibility and scalability.

Which solution will meet these requirements?

Answer options

• A. Use a role-based approach by creating an IAM role with an inline permissions policy that allows access to the secret. Update the IAM principals in the role trust policy as required.
• B. Deploy a VPC endpoint for Secrets Manager. Create and attach an endpoint policy that specifies the IAM principals that are allowed to access the secret. Update the list of IAM principals as required.
• C. Use a tag-based approach by attaching a resource policy to the secret. Apply tags to the secret and the IAM principals. Use the aws:PrincipalTag and aws:ResourceTag IAM condition keys to control access.
• D. Use a deny-by-default approach by using IAM policies to deny access to the secret explicitly. Attach the policies to an IAM group. Add all IAM principals to the IAM group. Remove principals from the group when they need access. Add the principals to the group again when access is no longer allowed.

Correct answer: C

Explanation

Using a tag-based approach (ABAC) with aws:PrincipalTag and aws:ResourceTag provides maximum flexibility and scalability because access is dynamically evaluated based on attributes, eliminating the need to constantly update IAM or resource policies. Role-based (Option A) and VPC endpoint-based (Option B) approaches require frequent manual policy updates, which do not scale well and increase administrative overhead. The deny-by-default group approach (Option D) is highly inefficient and creates significant risk of operational errors when managing group memberships.