STIGUI
V-254559CAT I — High severitySV-254559r1188303_rule

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

Rule version CNTR-R2-000130 · STIG v2 · 2026-05-13

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

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

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.

Identifiers

Group ID
V-254559
Group title
SRG-APP-000033-CTR-000095
Rule ID
SV-254559r1188303_rule
Check ID
C-58043r1188301_chk
Fix ID
F-57992r1188302_fix