| name | cis-k8s-v1111-1.3.5 |
| description | Ensure that the --root-ca-file argument is set as appropriate (Automated) |
| category | cis-k8s |
| version | 1.11.1 |
| author | cyberstrike-official |
| tags | ["cis","kubernetes","control-plane","controller-manager","service-account","profiling","credentials","tls"] |
| cis_id | 1.3.5 |
| cis_benchmark | CIS Kubernetes Benchmark v1.11.1 |
| tech_stack | ["kubernetes"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
1.3.5 Ensure that the --root-ca-file argument is set as appropriate (Automated)
Profile Applicability
Description
Allow pods to verify the API server's serving certificate before establishing connections.
Rationale
Processes running within pods that need to contact the API server must verify the API server's serving certificate. Failing to do so could be a subject to man-in-the-middle attacks.
Providing the root certificate for the API server's serving certificate to the controller manager with the --root-ca-file argument allows the controller manager to inject the trusted bundle into pods so that they can verify TLS connections to the API server.
Impact
You need to setup and maintain root certificate authority file.
Audit
Run the following command on the Control Plane node:
ps -ef | grep kube-controller-manager
Verify that the --root-ca-file argument exists and is set to a certificate bundle file containing the root certificate for the API server's serving certificate.
Remediation
Edit the Controller Manager pod specification file /etc/kubernetes/manifests/kube-controller-manager.yaml on the Control Plane node and set the --root-ca-file parameter to the certificate bundle file.
--root-ca-file=<path/to/file>
Default Value
By default, --root-ca-file is not set.
References
- https://kubernetes.io/docs/admin/kube-controller-manager/
- https://github.com/kubernetes/kubernetes/issues/11000
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|
| v8 | 3.10 Encrypt Sensitive Data in Transit | | x | x |
| v7 | 14.4 Encrypt All Sensitive Information in Transit | | x | x |
