Kubernetes Kubelet must enable tls-cert-file for client authentication to secure service.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-242425	CNTR-K8-001470	SV-242425r712631_rule		Medium

Description
Kubernetes container and pod configuration are maintained by Kubelet. Kubelet agents register nodes with the API Server, mount volume storage, and perform health checks for containers and pods. Anyone who gains access to Kubelet agents can effectively control applications within the pods and containers. Using authenticity protection, the communication can be protected against man-in-the-middle attacks/session hijacking and the insertion of false information into sessions. The communication session is protected by utilizing transport encryption protocols, such as TLS. TLS provides the Kubernetes API Server with a means to be able to authenticate sessions and encrypt traffic. To enable encrypted communication for Kubelet, the parameter etcd-cafile must be set. This parameter gives the location of the SSL Certificate Authority file used to secure Kubelet communication.

Description

Kubernetes container and pod configuration are maintained by Kubelet. Kubelet agents register nodes with the API Server, mount volume storage, and perform health checks for containers and pods. Anyone who gains access to Kubelet agents can effectively control applications within the pods and containers. Using authenticity protection, the communication can be protected against man-in-the-middle attacks/session hijacking and the insertion of false information into sessions. The communication session is protected by utilizing transport encryption protocols, such as TLS. TLS provides the Kubernetes API Server with a means to be able to authenticate sessions and encrypt traffic. To enable encrypted communication for Kubelet, the parameter etcd-cafile must be set. This parameter gives the location of the SSL Certificate Authority file used to secure Kubelet communication.

STIG	Date
Kubernetes Security Technical Implementation Guide	2021-04-14

Details

Check Text ( C-45700r712629_chk )
Change to the /etc/sysconfig/ directory on the Kubernetes Master Node. Run the commands: grep -i tls-cert-file kubelet If the setting "tls-cert-file" is not configured in the Kubernetes Kubelet, this is a finding.

Fix Text (F-45658r712630_fix)
Edit the Kubernetes Kuberlet file in the /etc/sysconfig directory on the Kubernetes Master Node. Set the argument "tls-cert-file" to an Approved Organization Certificate. Reset Kubelet service using the following command: service kubelet restart