Title

The Kubernetes Kubelet certificate authority must be owned by root. (Cat II impact)

Discussion

The Kubernetes kube proxy kubeconfig contain the argument and setting for the Control Planes. These settings contain network rules for restricting network communication between pods, clusters, and networks. If these files can be changed, data traversing between the Kubernetes Control Panel components would be compromised. Many of the security settings within the document are implemented through this file.

Check Content

On the Control Plane, run the command: ps -ef | grep kubelet If the "client-ca-file" option exists, this is a finding. Note the path to the config file (identified by --config). Run the command: grep -i clientCAFile <path_to_config_file> Note the path to the client ca file. Run the command: stat -c %U:%G <path_to_client_ca_file> If the command returns any non root:root file permissions, this is a finding.

Fix Text

On the Control Plane, run the command: ps -ef | grep kubelet Remove the "client-ca-file" option. Note the path to the config file (identified by --config). Run the command: grep -i clientCAFile <path_to_config_file> Note the path to the client ca file. Run the command: chown root:root <path_to_client_ca_file>

Additional Identifiers

Rule ID: SV-242450r918196_rule

Vulnerability ID: V-242450

Group Title: SRG-APP-000516-CTR-001325

Expert Comments

CCIs tied to check.

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