The Kubernetes kubelet static PodPath must not enable static pods.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-242397	CNTR-K8-000440	SV-242397r712547_rule		High

Description
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.

Description

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.

STIG	Date
Kubernetes Security Technical Implementation Guide	2021-04-14

Details

Check Text ( C-45672r712545_chk )
On the Master and Worker nodes, change to the /etc/sysconfig/ directory and run the command: grep -i staticPodPath kubelet If any of the nodes return a value for staticPodPath, this is a finding.

Fix Text (F-45630r712546_fix)
Edit the kubelet file on each node under the /etc/sysconfig directory to remove the staticPodPath setting and restart the kubelet service by executing the command: service kubelet restart