AWSOverview
Encrypt Kubernetes secrets, stored in etcd, using secrets encryption feature during Amazon EKS cluster creation.
Rationale
Kubernetes can store secrets that pods can access via a mounted volume. Today, Kubernetes secrets are stored with Base64 encoding, but encrypting is the recommended approach. Amazon EKS clusters version 1.13 and higher support the capability of encrypting your Kubernetes secrets using AWS Key Management Service (KMS) Customer Managed Keys (CMK). The only requirement is to enable the encryption provider support during EKS cluster creation. Use AWS Key Management Service (KMS) keys to provide envelope encryption of Kubernetes secrets stored in Amazon EKS. Implementing envelope encryption is considered a security best practice for applications that store sensitive data and is part of a defense in depth security strategy. Application-layer Secrets Encryption provides an additional layer of security for sensitive data, such as user defined Secrets and Secrets required for the operation of the cluster, such as service account keys, which are all stored in etcd. Using this functionality, you can use a key, that you manage in AWS KMS, to encrypt data at the application layer. This protects against attackers in the event that they manage to gain access to etcd.
Default value
By default secrets created using the Kubernetes API are stored in tmpfs and are encrypted at rest.
Remediation guidance
This process can only be performed during Cluster Creation. Enable 'Secrets Encryption' during Amazon EKS cluster creation as described in the links within the 'References' section.
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.
EKS Clusters without secrets encryption
Connectors
Covered asset types
Expected check: eq []
{
eksClusters(where:{
OR:[{encryptionConfig: null}, {encryptionConfig: {providerKeyARN: ""}}]
}) {
...AssetFragment
}
}
