AWS
Google CloudOverview
Identities that can be assumed or impersonated by external principals create a direct cross-tenant access path.
What this control checks
- AWS IAM roles with broad trust relationships.
- GCP service accounts with external access.
Why this matters
External trust should be explicit, minimal, and tightly controlled.
Remediation guidance
AWS remediation
- Edit role trust policy and remove broad principals.
- Allow only explicit trusted role/account ARNs.
- Add restrictive conditions for third-party use cases.
aws iam update-assume-role-policy --role-name <role-name> --policy-document file://trust-policy.json
GCP remediation
- Review service account IAM policy bindings.
- Remove external members that are not approved.
gcloud iam service-accounts get-iam-policy <sa>@<project-id>.iam.gserviceaccount.com
gcloud iam service-accounts remove-iam-policy-binding <sa>@<project-id>.iam.gserviceaccount.com --member="user:<[email protected]>" --role="roles/iam.serviceAccountTokenCreator"
References
- https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_update-role-trust-policy.html
- https://cloud.google.com/iam/docs/service-account-permissions
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.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting 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.
AWS Roles allowing external access
Connectors
Covered asset types
Expected check: eq []
{
AWSRolesWithExternalAccess {
...AssetFragment
}
}Google Cloud Service Accounts allowing external access
Connectors
Covered asset types
Expected check: eq []
{
GCPServiceAccountsWithExternalAccess{
...AssetFragment
}
}
