Cis K8S V1120 1.2.2

1.2.2 Ensure that the --token-auth-file parameter is not set (Automated)

Profile Applicability

• Level 1 - Master Node

Description

Do not use token based authentication.

Rationale

The token-based authentication utilizes static tokens to authenticate requests to the apiserver. The tokens are stored in clear-text in a file on the apiserver, and cannot be revoked or rotated without restarting the apiserver. Hence, do not use static token-based authentication.

Impact

You will have to configure and use alternate authentication mechanisms such as certificates. Static token based authentication could not be used.

Audit

Run the following command on the Control Plane node:

ps -ef | grep kube-apiserver

Verify that the --token-auth-file argument does not exist.

Alternative Audit Method

kubectl get pod -nkube-system -lcomponent=kube-apiserver -o=jsonpath='{range .items[*]}{.spec.containers[*].command} {"\n"}{end}' | grep '\--token-auth-file' | grep -i false

If the exit code is '1', then the control isn't present / failed

Remediation

Follow the documentation and configure alternate mechanisms for authentication. Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and remove the --token-auth-file=<filename> parameter.

Default Value

By default, --token-auth-file argument is not set.

References

1. https://kubernetes.io/docs/admin/authentication/#static-token-file
2. https://kubernetes.io/docs/admin/kube-apiserver/

CIS Controls