1.2.22 - Ensure that the --service-account-key-file argument is set as appropriate (Automated)

Views:

Profile applicability: Level 1 - Master Node

Explicitly set a service account public key file for service accounts on the apiserver.

By default, if no --service-account-key-file is specified to the apiserver, it uses the private key from the TLS serving certificate to verify service account tokens. To ensure that the keys for service account tokens could be rotated as needed, a separate public/private key pair should be used for signing service account tokens. Hence, the public key should be specified to the apiserver with --service-account-key-file.

Note

By default, --service-account-key-file argument is not set.

Impact

The corresponding private key must be provided to the controller manager. You would need to securely maintain the key file and rotate the keys based on your organization's key rotation policy.

Audit

Run the following command on the Control Plane node:

ps -ef | grep kube-apiserver

Verify that the --service-account-key-file argument exists and is set as appropriate.

Remediation

Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the Control Plane node and set the --service-account-key-file parameter to the public key file for service accounts:

--service-account-key-file=<filename>