Title

Kubernetes Kubelet must deny hostname override. (Cat II impact)

Discussion

Kubernetes allows for the overriding of hostnames. Allowing this feature to be implemented within the kubelets may break the TLS setup between the kubelet service and the API server. This setting also can make it difficult to associate logs with nodes if security analytics needs to take place. The better practice is to setup nodes with resolvable FQDNs and avoid overriding the hostnames.

Check Content

On the Control Plane and Worker nodes, run the command: ps -ef | grep kubelet If the option "--hostname-override" is present, this is a finding.

Fix Text

Run the command: systemctl status kubelet. Note the path to the drop-in file. Determine the path to the environment file(s) with the command: grep -i EnvironmentFile <path_to_drop_in_file>. Remove the "--hostname-override" option from any environment file where it is present. Restart the kubelet service using the following command: systemctl daemon-reload && systemctl restart kubelet

Additional Identifiers

Rule ID: SV-242404r918167_rule

Vulnerability ID: V-242404

Group Title: SRG-APP-000133-CTR-000290

Expert Comments

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