Kubernetes etcd must enable client authentication to secure service.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-242426	CNTR-K8-001480	SV-242426r961110_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. Etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive and should be accessible only by authenticated etcd peers in the etcd cluster. The parameter "--peer-client-cert-auth" must be set for etcd to check all incoming peer requests from the cluster for valid client certificates.

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. Etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive and should be accessible only by authenticated etcd peers in the etcd cluster. The parameter "--peer-client-cert-auth" must be set for etcd to check all incoming peer requests from the cluster for valid client certificates.

STIG	Date
Kubernetes Security Technical Implementation Guide	2024-06-10

Details

Check Text ( C-45701r927110_chk )
Change to the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Run the command: grep -i peer-client-cert-auth * If the setting "--peer-client-cert-auth" is not configured in the Kubernetes etcd manifest file or set to "false", this is a finding.

Fix Text (F-45659r927111_fix)
Edit the Kubernetes etcd manifest file in the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Set the value of "--peer-client-cert-auth" to "true" for the etcd.