The Kubernetes API server must have the secure port set.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-242389	CNTR-K8-000350	SV-242389r960792_rule		Medium

Description

By default, the API server will listen on what is rightfully called the secure port, port 6443. Any requests to this port will perform authentication and authorization checks. If this port is disabled, anyone who gains access to the host on which the Control Plane is running has full control of the entire cluster over encrypted traffic. Open the secure port by setting the API server's "--secure-port" flag to a value other than "0".

STIG	Date
Kubernetes Security Technical Implementation Guide	2024-08-22

Details

Check Text (C-45664r927085_chk)

Change to the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Run the command:

grep -i secure-port *

If the setting "--secure-port" is set to "0" or is not configured in the Kubernetes API manifest file, this is a finding.

Fix Text (F-45622r927086_fix)

Edit the Kubernetes API Server manifest file in the /etc/kubernetes/manifests directory on the Kubernetes Control Plane.

Set the value of "--secure-port" to a value greater than "0".