Title

The Kubernetes kubelet static PodPath must not enable static pods. (Cat I impact)

Discussion

Allowing kubelet to set a staticPodPath gives containers with root access permissions to traverse the hosting filesystem. The danger comes when the container can create a manifest file within the /etc/kubernetes/manifests directory. When a manifest is created within this directory, containers are entirely governed by the Kubelet not the API Server. The container is not susceptible to admission control at all. Any containers or pods that are instantiated in this manner are called "static pods" and are meant to be used for pods such as the API server, scheduler, controller, etc., not workload pods that need to be governed by the API Server.

Check Content

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: grep -i staticPodPath kubelet If any of the nodes return a value for staticPodPath, this is a finding.

Fix Text

Edit the kubelet file on each node under the --config directory and remove the staticPodPath setting. Reset Kubelet service using the following command: service kubelet restart

Additional Identifiers

Rule ID: SV-242397r879530_rule

Vulnerability ID: V-242397

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

Expert Comments

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