MCP-DEPLOY-01 — Container Hardening (Non-Root, Capabilities)#

Level: L2
Domain: DEPLOY

Requirement#

MCP servers deployed in containers MUST run as non-root users (UID != 0) and SHOULD drop all Linux capabilities unless specifically required.

Rationale#

Running as root amplifies impact of any vulnerability. Container escape exploits often require root privileges.

Scope#

Docker, Kubernetes, or other container deployments.

Required Evidence#

1. Dockerfile showing USER 1000 or named user
2. Kubernetes pod spec: runAsNonRoot: true, runAsUser: 1000
3. Capabilities dropped: drop: [ALL]
4. Test: whoami inside container → not root

Verification Guidance#

Static#

# Good
FROM node:20-slim
RUN useradd -u 1000 mcpuser
USER 1000
CMD ["node", "server.js"]

# Good (Kubernetes)
securityContext:
  runAsNonRoot: true
  runAsUser: 1000
  capabilities:
    drop: [ALL]

Dynamic#

• docker exec <container> whoami → should output non-root user
• Attempt to write to /usr/bin → should fail

Mappings#

• OWASP MCP Top 10: MCP-09 (Shadow MCP Servers - deployment security)
• Docker CIS Benchmark: 5.3 (Ensure containers do not run as root)
• NIST SP 800-190

Exceptions & Compensating Controls#

NOT_APPLICABLE: Non-containerized deployments (but principle of least privilege still applies via system users).

References#

• Docker security best practices
• Trend Micro: “Using Containers to Secure MCP Infrastructure” (Sept 2024)