Guides

Ensure that the admission control plugin SecurityContextDeny is set if PodSecurityPolicy is not used (API Server)

The SecurityContextDeny admission controller can be used to deny pods which make use of some SecurityContext fields which could allow for privilege escalation in the cluster. This should be used if the relevant CloudGuard Admission Control rules have not been configured or where PodSecurityPolicy is not in place within the cluster.

Suggest Edits

Risk Level: High
Cloud Entity: Pods
CloudGuard Rule ID: D9.K8S.IAM.47
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 'enable-admission-plugins' and value like '%SecurityContextDeny%']]

REMEDIATION

Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the --enable-admission-plugins parameter to include SecurityContextDeny, unless the relevant CloudGuard Admission Control rule has been configured or PodSecurityPolicy is already in place.

References

  1. https://kubernetes.io/docs/admin/kube-apiserver/
  2. https://kubernetes.io/docs/admin/admission-controllers/#securitycontextdeny
    https://kubernetes.io/docs/user-guide/pod-security-policy/#working-with-rbac

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 v1.5.1
  • CIS Kubernetes Benchmark v1.6.1

Updated over 1 year ago