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V-254559

CAT I (High)

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

Rule ID

SV-254559r1188303_rule

STIG

Rancher Government Solutions RKE2 Security Technical Implementation Guide

Version

V2R6

CCIs

CCI-000213

Discussion

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".

Check Content

Ensure read-only-port is set so anonymous requests will be rejected.

Run the following 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

Edit the RKE2 configuration file on all RKE2 hosts, located at /etc/rancher/rke2/config.yaml, to contain the following: kubelet-arg: --read-only-port=0

If configuration files are updated on a host, restart the RKE2 service using the command "systemctl restart rke2-server" for server hosts and "systemctl restart rke2-agent" for agent hosts.