Title

Kubernetes Kubelet must enable tls-cert-file for client authentication to secure service. (Cat II impact)

Discussion

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.

Check Content

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

Edit the Kubernetes Kubelet file in the /etc/sysconfig directory on the Kubernetes Control Plane. Set the argument "tls-cert-file" to an Approved Organization Certificate. Reset Kubelet service using the following command: service kubelet restart

Additional Identifiers

Rule ID: SV-242425r879636_rule

Vulnerability ID: V-242425

Group Title: SRG-APP-000219-CTR-000550

Expert Comments

CCIs tied to check.

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