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-242397r863973_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	2022-09-13

Details

Check Text ( C-45672r863791_chk )
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 (F-45630r863792_fix)
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