The Kubernetes Kubelet must have the read-only port flag disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-254559	CNTR-R2-000130	SV-254559r870254_rule		High

Description
Kubelet serves a small REST API with read access to port 10255. The read-only port for Kubernetes provides no authentication or authorization security control. Providing unrestricted access on port 10255 exposes Kubernetes pods and containers to malicious attacks or compromise. Port 10255 is deprecated and should be disabled. Close the read-only-port by setting the API server's read-only port flag to "0".

Description

Kubelet serves a small REST API with read access to port 10255. The read-only port for Kubernetes provides no authentication or authorization security control. Providing unrestricted access on port 10255 exposes Kubernetes pods and containers to malicious attacks or compromise. Port 10255 is deprecated and should be disabled. Close the read-only-port by setting the API server's read-only port flag to "0".

STIG	Date
Rancher Government Solutions RKE2 Security Technical Implementation Guide	2022-10-13

Details

Check Text ( C-58043r870253_chk )
Ensure read-only-port is set correctly so anonymous requests will be rejected. Run this command on each node: /bin/ps -ef \| grep kubelet \| grep -v grep If --read-only-port is not set to "0" or is not configured, this is a finding.

Fix Text (F-57992r859246_fix)
Edit the Kubernetes Kubelet file etc/rancher/rke2/config.yaml on the RKE2 Control Plane and set the following: --read-only-port=0 Once configuration file is updated, restart the RKE2 Agent. Run the command: systemctl restart rke2-agent