Title

Kubernetes API Server must have the SSL Certificate Authority set. (Cat II impact)

Discussion

Kubernetes control plane and external communication are managed by API Server. The main implementation of the API Server is to manage hardware resources for pods and containers using horizontal or vertical scaling. Anyone who can access the API Server can effectively control the Kubernetes architecture. 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 authenticate sessions and encrypt traffic. To enable encrypted communication for API Server, the parameter client-ca-file must be set. This parameter gives the location of the SSL Certificate Authority file used to secure API Server communication.

Check Content

Change to the /etc/kubernetes/manifests/ directory on the Kubernetes Control Plane. Run the command: grep -i client-ca-file * If the setting feature client-ca-file is not set in the Kubernetes API server manifest file or contains no value, this is a finding.

Fix Text

Edit the Kubernetes API Server manifest file in the /etc/kubernetes/manifests directory on the Kubernetes Control Plane. Set the value of "--client-ca-file" to path containing Approved Organizational Certificate.

Additional Identifiers

Rule ID: SV-242419r961110_rule

Vulnerability ID: V-242419

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

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.