The Kubernetes KubeletConfiguration file must be owned by root.

STIG ID: CNTR-K8-000880  |  SRG: SRG-APP-000133-CTR-000300 |  Severity: medium |  CCI: CCI-001499 |  Vulnerability Id: V-242406

Vulnerability Discussion

The kubelet configuration file contains the runtime configuration of the kubelet service. If an attacker can gain access to this file, changes can be made to open vulnerabilities and bypass user authorizations inherent within Kubernetes with RBAC implemented.

Check

On the Kubernetes Control Plane and Worker nodes, run the command:
ps -ef | grep kubelet

Check the config file (path identified by: --config):

Change to the directory identified by --config (example /etc/sysconfig/) run the command:
ls -l kubelet

Each kubelet configuration file must be owned by root:root.

If any manifest file is not owned by root:root, this is a finding.

Fix

On the Control Plane and Worker nodes, change to the --config directory. Run the command:
chown root:root kubelet

To verify the change took place, run the command:
ls -l kubelet

The kubelet file should now be owned by root:root.