AWSOverview
Configure the Cluster Service Account with Storage Object Viewer Role to only allow read-only access to Amazon ECR.
Rationale
The Cluster Service Account does not require administrative access to Amazon ECR, only requiring pull access to containers to deploy onto Amazon EKS. Restricting permissions follows the principles of least privilege and prevents credentials from being abused beyond the required role.
Impact
A separate dedicated service account may be required for use by build servers and other robot users pushing or managing container images.
Audit
Review AWS ECS worker node IAM role (NodeInstanceRole) IAM Policy Permissions to verify that they are set and the minimum required level.
Default value
If you used eksctl or the AWS CloudFormation templates in Getting Started with Amazon EKS to create your cluster and worker node groups, these IAM permissions are applied to your worker node IAM role by default.
Remediation guidance
You can use your Amazon ECR images with Amazon EKS, but you need to satisfy the following prerequisites. The Amazon EKS worker node IAM role (NodeInstanceRole) that you use with your worker nodes must n ot include permissions with write access level.
References
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.
EKSNodeGroup roles with write access to ECR
Connectors
Covered asset types
Expected check: eq []
{
EKSNodeGroupRolesWithWriteAccessToECR {
...AssetFragment
}
}
