1.1.26 Ensure that the --service-account-key-file argument is set as appropriate

Information

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

Rationale:

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`.

Solution

Edit the `/etc/kubernetes/apiserver` file on the master node and set the `KUBE_API_ARGS` parameter to `'--service-account-key-file='`: `KUBE_API_ARGS='--service-account-key-file='`

Based on your system, restart the `kube-apiserver` service. For example: `systemctl restart kube-apiserver.service`

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.

See Also

https://workbench.cisecurity.org/files/1738

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-5(2), CSCv6|3

Plugin: Unix

Control ID: 1f372f5582d9efa6514e8ab1407a593843611fdfa04b02bd5a57094b6493ebc4