Prevent Host Ports 1.1.5

Enforces that no container is able to use the ports of a node it is running on.

Note that this policy is part of the following security standards:

k8s/baseline: Minimally restrictive policy while preventing known privilege escalations.
k8s/restricted: Heavily restricted policy, following current Pod hardening best practices.
nist/SP.800-190: NIST Special Publication 800-190 - Application Container Security Guide: Section 3.4.3
bsi/containerization: BSI IT-Grundschutz "Containerisierung": Section: SYS.1.6.A16
bsi/kubernetes: BSI IT-Grundschutz "Kubernetes": Section: APP.4.4.A7

Host Access
Security
bsi/containerization
bsi/kubernetes
k8s/baseline
k8s/restricted
nist/SP.800-190

Applies to

Example

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:1.14.2
          ports:
            - containerPort: 80
-             hostPort: 8080

Risk acceptance

Use the annotation securitytower.io/policy.exclusion.preventhostports as on the example below.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: your-deployment
  annotations:
    securitytower.io/policy.exclusion.preventhostports: |-
      This container must use the host ports for following reasons.
...