Title

The Kubernetes Kubelet must have anonymous authentication disabled. (Cat I impact)

Discussion

A user who has access to the Kubelet essentially has root access to the nodes contained within the Kubernetes Control Plane. To control access, users must be authenticated and authorized. By allowing anonymous connections, the controls put in place to secure the Kubelet can be bypassed. Setting anonymous authentication to "false" also disables unauthenticated requests from kubelets. While there are instances where anonymous connections may be needed (e.g., health checks) and Role-Based Access Controls (RBAC) are in place to limit the anonymous access, this access must be disabled and only enabled when necessary.

Check Content

Change to the /etc/sysconfig/ directory on the Kubernetes Master Node. Run the command: grep -i anonymous-auth kubelet If the setting "anonymous-auth" is set to "true" or the parameter not set in the Kubernetes Kubelet configuration file, this is a finding.

Fix Text

Edit the Kubernetes Kubelet file in the/etc/sysconfig/ directory on the Kubernetes Master Node. Set the argument "--anonymous-auth" to "false". Restart kubelet service using command: service kubelet restart

Additional Identifiers

Rule ID: SV-242391r712529_rule

Vulnerability ID: V-242391

Group Title: SRG-APP-000033-CTR-000090

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.