Security Context Deny Admission Control Plugin Not Set

• Query id: 6a68bebe-c021-492e-8ddb-55b0567fb768
• Query name: Security Context Deny Admission Control Plugin Not Set
• Platform: Kubernetes
• Severity: Medium
• Category: Insecure Configurations
• CWE: 284
• URL: Github

Description

When using kube-apiserver command, the '--enable-admission-plugins' flag should have 'SecurityContextDeny' plugin and the plugin should be correctly configured in AdmissionControl Config file when 'PodSecurityPolicy' plugin is not set
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--enable-admission-plugins=AlwaysAdmit"]
  restartPolicy: OnFailure

Code samples without security vulnerabilities

Negative test num. 1 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--enable-admission-plugins=SecurityContextDeny", "--admission-control-config-file=path/to/plugin/config/file.yaml"]
  restartPolicy: OnFailure

Negative test num. 2 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver","--enable-admission-plugins=SecurityContextDeny", "--admission-control-config-file=path/to/plugin/config/file.yaml"]
      args: []
  restartPolicy: OnFailure

Negative test num. 3 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver","--enable-admission-plugins=PodSecurityPolicy", "--admission-control-config-file=path/to/plugin/config/file.yaml"]
      args: []
  restartPolicy: OnFailure