---
title: "HOST-K8S-001 Kubelet Allows Anonymous or Unauthorised Access"
canonical: https://openvapt.com/checks/HOST-K8S-001.html
html: https://openvapt.com/checks/HOST-K8S-001.html
site: OpenVAPT, https://openvapt.com/
license: OpenVAPT Source-Available Licence 1.3, https://openvapt.com/legal/licence-text.html
modified: 2026-10-14
version: 0.1.0-alpha.6
---

# HOST-K8S-001 Kubelet Allows Anonymous or Unauthorised Access

Checks the kubelet configuration for anonymous authentication, AlwaysAllow authorisation or the unauthenticated read-only port.

- Domain: Server
- Severity: Critical
- Control category: Identity and Authentication
- Fix effort: medium
- CVSS v3.1 vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
- CIS Controls v8: 5.2
- NIST CSF 2.0: PR.AA-01
- CWE: CWE-306, CWE-862
- OWASP Top 10 2021: A01:2021, A07:2021
- NIST SP 800-53 Rev. 5: AC-3, IA-2

## Why It Matters

The kubelet API can run commands in every pod on the node. With anonymous access or AlwaysAllow, anyone who can reach port 10250 controls the node's workloads; the read-only port 10255 leaks pod and environment details.

## How It Detects

Reads /var/lib/kubelet/config.yaml and looks for authentication.anonymous.enabled: true, authorization.mode: AlwaysAllow, or a non-zero readOnlyPort.

## How to Fix

Set authentication.anonymous.enabled: false, authorization.mode: Webhook and readOnlyPort: 0 in the kubelet configuration, then restart the kubelet.

## How to Verify

```
grep -A2 -E 'anonymous|authorization|readOnlyPort' /var/lib/kubelet/config.yaml
```

## Learn the Theory

- [P9 Containers and Kubernetes](https://openvapt.com/academy/p9.md)

## References

- [Kubernetes documentation, Kubelet authentication and authorization](https://kubernetes.io/docs/reference/access-authn-authz/kubelet-authn-authz/)
- [Kubernetes documentation, Securing a cluster](https://kubernetes.io/docs/tasks/administer-cluster/securing-a-cluster/)

## Source Code

https://github.com/OpenVAPT/openvapt/blob/574f7f3333c44b75a3c649e2d93a76d507f75adf/internal/checks/host/containers.go

Run it: `openvapt scan --only HOST-K8S-001`. Read it offline: `openvapt explain HOST-K8S-001`.

---

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