Ensure that the --authorization-mode argument includes Node (API Server)

Restrict kubelet nodes to reading only objects associated with them. The Node authorization mode only allows kubelets to read Secret, ConfigMap, PersistentVolume, and PersistentVolumeClaim objects associated with their nodes.

Risk Level: High
Cloud Entity: Pods
CloudGuard Rule ID: D9.K8S.IAM.46
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 'authorization-mode' and value like '%Node%']]

REMEDIATION

Edit the API server pod specification file /etc/kubernetes/manifests/kube-
apiserver.yaml on the Control Plane node and set the --authorization-mode parameter
to a value that includes Node.
--authorization-mode=Node,RBAC

References

  1. https://kubernetes.io/docs/admin/kube-apiserver/
  2. https://kubernetes.io/docs/admin/authorization/node/
  3. https://github.com/kubernetes/kubernetes/pull/4607674
  4. https://acotten.com/post/kube17-security

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