Ensure that the container is restricted from acquiring additional privileges

HighLevel 1Automateddocker

Description

no-new-privileges stops processes in the container gaining privileges through setuid/setgid binaries. Compliant when it is set daemon-wide in daemon.json (container SecurityOpt then stays empty) or every running container has it in SecurityOpt. 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

grep -Eq '"no-new-privileges"[[:space:]]*:[[:space:]]*true' /etc/docker/daemon.json 2>/dev/null && { echo compliant; exit 0; }; ids=$(docker ps -q) || exit 1; [ -z "$ids" ] && { echo compliant; exit 0; }; out=$(docker inspect --format '{{.Name}}{{range .HostConfig.SecurityOpt}} {{.}}{{end}}' $ids) || exit 1; bad=$(printf '%s\n' "$out" | awk '!/no-new-privileges(:true|=true)?( |$)/{print $1}'); [ -z "$bad" ] && echo compliant || printf '%s\n' "$bad"

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run containers with --security-opt=no-new-privileges (compose: security_opt: ["no-new-privileges:true"]) or set "no-new-privileges": true in /etc/docker/daemon.json.

Properties

Operating systems: Any
Tags: dockerruntime
Reference: CIS Docker Benchmark v1.9.0 - 5.26 Ensure that the container is restricted from acquiring additional privileges

Check this host

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

shell

tmaegis scan --target docker