TMA-KUBERNETES-5.2.2

Minimize the admission of privileged containers

CriticalLevel 1Automatedkubernetes

Description

Do not generally permit containers to be run with the securityContext.privileged flag set to true. Requires kubectl with cluster-wide read access (KUBECONFIG); system namespaces are excluded and listed resources must be remediated or documented as exceptions. The benchmark marks this Manual; this audit automates its kubectl inventory step.

How it is checked

Audit method: Shell command

shell

out=$(kubectl get pods -A -o go-template='{{range .items}}{{$ns:=.metadata.namespace}}{{$p:=.metadata.name}}{{range .spec.containers}}{{$ns}} {{$p}} {{.name}} {{with .securityContext}}{{.privileged}}{{end}}{{"\n"}}{{end}}{{range .spec.initContainers}}{{$ns}} {{$p}} {{.name}} {{with .securityContext}}{{.privileged}}{{end}}{{"\n"}}{{end}}{{range .spec.ephemeralContainers}}{{$ns}} {{$p}} {{.name}} {{with .securityContext}}{{.privileged}}{{end}}{{"\n"}}{{end}}{{end}}') || exit 1
bad=$(printf '%s\n' "$out" | awk -v ex='^(kube-system|kube-public|kube-node-lease)$' 'NF && $1 !~ ex && ($4=="true")')
if [ -z "$bad" ]; then echo compliant; else printf '%s\n' "$bad" | head -n 25; fi

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Add policies to each namespace in the cluster which has user workloads to restrict the admission of privileged containers.

Properties

Operating systems: Any
Tags: kubernetespoliciespod-security
Reference: CIS Kubernetes Benchmark v2.1.0 - 5.2.2 Minimize the admission of privileged containers

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target kubernetes