AWSOverview
The list of principals able to assume a role should be limited as much as possible, and should not include "*", meaning that any authenticated identity across all of AWS can assume the role.
Remediation guidance
AWS remediation
Console
- Open IAM role trust policy.
- Remove broad principals such as wildcard principal.
- Allow only explicit trusted principals.
- Add conditions like sts:ExternalId when third-party access is required.
AWS CLI
aws iam update-assume-role-policy \
--role-name <role-name> \
--policy-document file://trust-policy.json
References
- https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_update-role-trust-policy.html
- https://docs.aws.amazon.com/cli/latest/reference/iam/update-assume-role-policy.html
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
AWS
Use AWS Organizations guardrails, AWS Config rules or conformance packs where they fit, approved account baselines, and IaC modules so new resources inherit the secure setting.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
IAM Role can be assumed only by specific Principals
Connectors
AWS
Covered asset types
IAMRole
Expected check: eq []
{iamRoles(where:{hasIAMAssumeRolePolicyStatement_SOME:{hasIAMAssumeRolePolicyPrincipal_SOME:{value:"*"}}}){...AssetFragment}}
