cis-k8s-v1110-1-2-14

name	cis-k8s-v1110-1.2.14
description	Ensure that the admission control plugin NodeRestriction is set (Automated)
category	cis-k8s
version	1.11.0
author	cyberstrike-official
tags	["cis","kubernetes","control-plane","api-server","admission-plugins","node-restriction","kubelet-security"]
cis_id	1.2.14
cis_benchmark	CIS Kubernetes Benchmark v1.11.0
tech_stack	["kubernetes"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

1.2.14 Ensure that the admission control plugin NodeRestriction is set (Automated)

Profile Applicability

• Level 2 - Master Node

Description

Limit the Node and Pod objects that a kubelet could modify.

Rationale

Using the NodeRestriction plug-in ensures that the kubelet is restricted to the Node and Pod objects that it could modify as defined. Such kubelets will only be allowed to modify their own Node API object, and only modify Pod API objects that are bound to their node.

Impact

None

Audit

Run the following command on the Control Plane node:

ps -ef | grep kube-apiserver

Verify that the --enable-admission-plugins argument is set to a value that includes NodeRestriction.

Remediation

Follow the Kubernetes documentation and configure NodeRestriction plug-in on kubelets. Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the --enable-admission-plugins parameter to a value that includes NodeRestriction.

--enable-admission-plugins=...,NodeRestriction,...

Default Value

By default, NodeRestriction is not set.

References

1. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/
2. https://kubernetes.io/docs/reference/access-authn-authz/admission-controllers/#noderestriction
3. https://kubernetes.io/docs/reference/access-authn-authz/node/

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	13.10 Perform Application Layer Filtering			*
v7	12.9 Deploy Application Layer Filtering Proxy Server