undermybelt Performing Docker Bench Security Assessment
Overview
Docker Bench for Security is an open-source script that checks dozens of common best practices around deploying Docker containers in production. Based on the CIS Docker Benchmark, it audits host configuration, Docker daemon settings, container images, runtime configurations, and security operations to generate a compliance report with pass/fail/warn results.
When to Use
- When conducting security assessments that involve performing docker bench security assessment
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing
Prerequisites
- Docker Engine installed and running
- Root or sudo access on Docker host
- Docker Bench Security script or container image
Workflow
Step 1: Run Docker Bench Security
# Run as a container (recommended)
docker run --rm --net host --pid host --userns host --cap-add audit_control \
-e DOCKER_CONTENT_TRUST=$DOCKER_CONTENT_TRUST \
-v /etc:/etc:ro \
-v /usr/bin/containerd:/usr/bin/containerd:ro \
-v /usr/bin/runc:/usr/bin/runc:ro \
-v /usr/lib/systemd:/usr/lib/systemd:ro \
-v /var/lib:/var/lib:ro \
-v /var/run/docker.sock:/var/run/docker.sock:ro \
--label docker_bench_security \
docker/docker-bench-security
# Run with JSON output
docker run --rm --net host --pid host --userns host --cap-add audit_control \
-v /etc:/etc:ro \
-v /var/lib:/var/lib:ro \
-v /var/run/docker.sock:/var/run/docker.sock:ro \
docker/docker-bench-security -l /dev/stdout 2>/dev/null | tee docker-bench-results.json
# Run specific sections only
docker run --rm --net host --pid host --userns host \
-v /var/run/docker.sock:/var/run/docker.sock:ro \
docker/docker-bench-security -c container_images,container_runtime
Step 2: Interpret Results
[INFO] 1 - Host Configuration
[PASS] 1.1.1 - Ensure a separate partition for containers has been created
[WARN] 1.1.2 - Ensure only trusted users are allowed to control Docker daemon
[PASS] 1.1.3 - Ensure auditing is configured for the Docker daemon
[INFO] 2 - Docker daemon configuration
[FAIL] 2.1 - Run the Docker daemon as a non-root user
[PASS] 2.2 - Ensure network traffic is restricted between containers on the default bridge
Step 3: Remediate Common Failures
# Fix 2.2: Restrict inter-container communication
echo '{"icc": false}' | sudo tee /etc/docker/daemon.json
# Fix 2.17: Restrict containers from acquiring new privileges
echo '{"no-new-privileges": true}' | sudo tee -a /etc/docker/daemon.json
# Fix 5.3: Restrict Linux kernel capabilities
# Use --cap-drop ALL in docker run commands
# Fix 5.12: Mount container's root filesystem as read only
# Use --read-only flag in docker run commands
# Restart Docker daemon after configuration changes
sudo systemctl restart docker
Step 4: Automate Scheduled Assessments
# docker-compose for scheduled assessment
version: '3.8'
services:
bench-security:
image: docker/docker-bench-security
network_mode: host
pid: host
userns_mode: host
cap_add:
- audit_control
volumes:
- /etc:/etc:ro
- /var/lib:/var/lib:ro
- /var/run/docker.sock:/var/run/docker.sock:ro
- ./results:/results
command: -l /results/bench-$(date +%Y%m%d).log
deploy:
restart_policy:
condition: none
Validation Commands
# Verify remediation
docker run --rm docker/docker-bench-security 2>&1 | grep -E "(PASS|FAIL|WARN)" | sort | uniq -c
# Count results by type
docker run --rm docker/docker-bench-security 2>&1 | grep -c "PASS"
docker run --rm docker/docker-bench-security 2>&1 | grep -c "FAIL"
docker run --rm docker/docker-bench-security 2>&1 | grep -c "WARN"