Ensure that the Docker socket is not mounted inside any containers

CriticalLevel 1Automateddocker

Description

A container with the Docker socket mounted can start privileged containers and fully control the host. The audit inspects every running container (docker ps -q) and prints the offending names; a host with no running containers is compliant.

How it is checked

Audit method: Shell command

shell

ids=$(docker ps -q) || exit 1; [ -z "$ids" ] && { echo compliant; exit 0; }; out=$(docker inspect --format '{{.Name}}{{range .Mounts}} {{.Source}}{{end}}' $ids) || exit 1; bad=$(printf '%s\n' "$out" | awk '/docker\.sock/{print $1}'); [ -z "$bad" ] && echo compliant || printf '%s\n' "$bad"

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Redeploy without mounting /var/run/docker.sock; use a narrowly-scoped API proxy if a container genuinely needs Docker API access.

Properties

Operating systems: Any
Tags: dockerruntime
Reference: CIS Docker Benchmark v1.9.0 - 5.32 Ensure that the Docker socket is not mounted inside any containers

Check this host

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

shell

tmaegis scan --target docker