# Cis K8S V1120 1.2.4

> Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate (Automated)

- Skill: `cyberstrikeus/cis-k8s-v1120-1-2-4` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-k8s-v1120-1-2-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-k8s-v1120-1-2-4/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-k8s-v1120-1-2-4

---


# 1.2.4 Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate (Automated)

## Profile Applicability

- Level 1 - Master Node

## Description

Enable certificate based kubelet authentication.

## Rationale

The apiserver, by default, does not authenticate itself to the kubelet's HTTPS endpoints. The requests from the apiserver are treated anonymously. You should set up certificate-based kubelet authentication to ensure that the apiserver authenticates itself to kubelets when submitting requests.

## Impact

You require TLS to be configured on apiserver as well as kubelets.

## Audit

Run the following command on the Control Plane node:

```bash
ps -ef | grep kube-apiserver
```

Verify that the `--kubelet-client-certificate` and `--kubelet-client-key` arguments exist and they are set as appropriate.

### Alternative Audit

```bash
kubectl get pod -nkube-system -lcomponent=kube-apiserver -o=jsonpath='{range .items[]}{.spec.containers[].command} {"\n"}{end}' | grep '--kubelet-client-certificate' | grep -i false
```

If the exit code is '1', then the control isn't present / failed

## Remediation

Follow the Kubernetes documentation and set up the TLS connection between the apiserver and kubelets. Then, edit API server pod specification file `/etc/kubernetes/manifests/kube-apiserver.yaml` on the Control Plane node and set the kubelet client certificate and key parameters as below.

```
--kubelet-client-certificate=<path/to/client-certificate-file>
--kubelet-client-key=<path/to/client-key-file>
```

## Default Value

By default, certificate-based kubelet authentication is not set.

## References

1. [https://kubernetes.io/docs/admin/kube-apiserver/](https://kubernetes.io/docs/admin/kube-apiserver/)
2. [https://kubernetes.io/docs/admin/kubelet-authentication-authorization/](https://kubernetes.io/docs/admin/kubelet-authentication-authorization/)
3. [https://kubernetes.io/docs/concepts/cluster-administration/master-node-communication/#apiserver---kubelet](https://kubernetes.io/docs/concepts/cluster-administration/master-node-communication/#apiserver---kubelet)

## CIS Controls

| Controls Version | Control                                                                       | IG 1 | IG 2 | IG 3 |
| ---------------- | ----------------------------------------------------------------------------- | ---- | ---- | ---- |
| v8               | 16.11 Leverage Vetted Modules or Services for Application Security Components |      | \*   | \*   |
| v7               | 9 Limitation and Control of Network Ports, Protocols, and Services            |      |      |      |