Node Restriction Admission Control Plugin Not Set

• Query id: 33fc6923-6553-4fe6-9d3a-4efa51eb874b
• Query name: Node Restriction Admission Control Plugin Not Set
• Platform: Kubernetes
• Severity: High
• Category: Access Control
• URL: Github

Description

When using kube-apiserver command, the --enable-admission-plugins flag should have 'NodeRestriction' plugin and the plugin should be correctly configured in AdmissionControl Config file
Documentation

Code samples

Code samples with security vulnerabilities

Postitive 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=NodeRestriction", "--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=NodeRestriction", "--admission-control-config-file=path/to/plugin/config/file.yaml"]
      args: []
  restartPolicy: OnFailure