Information
In multi-account environments, IAM user centralization facilitates greater user control. User access beyond the initial account is provided through role assumption. Centralization of users can be accomplished through federation with an external identity provider or through the use of AWS Organizations. AWS IAM Identity Center (formerly AWS SSO) is the recommended approach for centralized user management in AWS Organizations.
Centralizing IAM user management to a single identity store reduces complexity and the likelihood of access management errors. Using AWS IAM Identity Center further simplifies access management and reduces reliance on legacy per-account federation configurations.
NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.
Solution
The remediation procedure will vary based on the organization's implementation of identity federation and or AWS Organizations.
Ensure the following:
- IAM users are centrally managed through a single identity provider
- Local IAM users are removed from member accounts, except for service accounts where required
- Access to accounts is granted through role assumption
- Where possible, migrate to AWS IAM Identity Center for centralized access management
- Avoid legacy per-account federation configurations
Impact:
Managing IAM users independently across multiple accounts increases the risk of inconsistent access controls, orphaned accounts, and excessive permissions.