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Kubernetes API Server must have the SSL Certificate Authority set.


Finding ID Version Rule ID IA Controls Severity
V-242419 CNTR-K8-001410 SV-242419r863994_rule Medium
Kubernetes control plane and external communication is 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 be able to authenticate sessions and encrypt traffic. To enable encrypted communication for API Server, the parameter etcd-cafile must be set. This parameter gives the location of the SSL Certificate Authority file used to secure API Server communication.
Kubernetes Security Technical Implementation Guide 2022-12-02


Check Text ( C-45694r863845_chk )
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 (F-45652r863846_fix)
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.