Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate (API Server)

Enable certificate based kubelet authentication. The apiserver, by default, does not authenticate itself to the kubelet's HTTPS endpoints. The requests from the apiserver are treated anonymously. You should set up certificate-based kubelet authentication to ensure that the apiserver authenticates itself to kubelets when submitting requests.

Risk Level: High
Cloud Entity: Pods
CloudGuard Rule ID: D9.K8S.IAM.07
Covered by Spectral: Yes
Category: Compute

GSL LOGIC

KubernetesPod where labels contain [value='kube-apiserver'] and namespace = 'kube-system' should have spec.containers with [(parsedArgs contain [key like 'kubelet-client-certificate' ]) and (parsedArgs contain [key like 'kubelet-client-key' ])]

REMEDIATION

Follow the Kubernetes documentation and set up the TLS connection between the
apiserver and kubelets. Then, edit API server pod specification file
$apiserverconf on the master node and set the
kubelet client certificate and key parameters as below.
--kubelet-client-certificate=<path/to/client-certificate-file>
--kubelet-client-key=<path/to/client-key-file>

References

  1. https://kubernetes.io/docs/admin/kube-apiserver/
  2. https://kubernetes.io/docs/admin/kubelet-authentication-authorization/
  3. https://kubernetes.io/docs/concepts/cluster-administration/master-node-communication/#apiserver---kubelet

Pods

Pods are the smallest deployable units of computing that can be created and managed in Kubernetes.A Pod is a group of one or more containers (such as Docker containers), with shared storage/network, and a specification for how to run the containers.

Compliance Frameworks

  • CIS Kubernetes Benchmark v1.20
  • CIS Kubernetes Benchmark v1.23
  • CIS Kubernetes Benchmark v1.24
  • CIS Kubernetes Benchmark v1.4.0
  • CIS Kubernetes Benchmark v1.5.1
  • CIS Kubernetes Benchmark v1.6.1
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices