KNEL-AIMiddleware/docs/audit/2026-02-20/03-docker-compose-security.md

Docker Compose Security Audit

Date: 2026-02-20 Auditor: External Security Review Scope: docker-compose.yml and container orchestration

Executive Summary

Metric	Value
Total Services	40+
High Severity Issues	3
Medium Severity Issues	1
Low Severity Issues	1

Detailed Findings

1. Docker Socket Mount (HIGH)

Severity: HIGH Affected Services: docker-mcp, mcp-ansible CWE: CWE-250 (Execution with Unnecessary Privileges)

Description

Two services mount the Docker socket, granting full Docker daemon access:

# docker-mcp
volumes:
  - /var/run/docker.sock:/var/run/docker.sock

# mcp-ansible
volumes:
  - /var/run/docker.sock:/var/run/docker.sock

This provides equivalent access to root on the host system.

Impact

• Full control over all containers on host
• Ability to mount host filesystem
• Potential for container escape
• Access to secrets in other containers

Risk Assessment

• Necessary for Function: Yes - these services manage Docker/containers
• Mitigation Required: Yes

Recommendation

1. Run these services with explicit user constraints where possible
2. Document the privilege requirement clearly
3. Consider socket proxy (docker-socket-proxy) for least privilege
4. Isolate on dedicated management nodes in production

# Alternative with socket proxy
services:
  docker-mcp:
    environment:
      - DOCKER_HOST=tcp://docker-proxy:2375
    depends_on:
      - docker-proxy
  
  docker-proxy:
    image: tecnativa/docker-socket-proxy
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      - CONTAINERS=1
      - IMAGES=1
      # Only allow specific operations

---

2. Kubernetes Config Mount (HIGH)

Severity: HIGH Affected Service: kubernetes-mcp CWE: CWE-250 (Execution with Unnecessary Privileges)

Description

The kubernetes-mcp service mounts kubeconfig:

volumes:
  - ~/.kube/config:/home/appuser/.kube/config:ro

This grants Kubernetes cluster admin access to the container.

Impact

• Full control over Kubernetes cluster
• Access to all secrets in cluster
• Ability to deploy privileged workloads
• Cluster admin equivalent access

Risk Assessment

• Necessary for Function: Yes - required for Kubernetes management
• Mitigation Required: Yes

Recommendation

1. Use read-only mount (:ro flag) - already implemented
2. Consider ServiceAccount tokens instead of kubeconfig
3. Implement RBAC with minimal required permissions
4. Document required permissions clearly

---

3. Privileged Access Pattern (MEDIUM)

Severity: MEDIUM Affected: Multiple services requiring system access CWE: CWE-269 (Improper Privilege Management)

Description

Several services require elevated privileges for their function:

Service	Privilege Type	Justification
docker-mcp	Docker socket	Container management
mcp-ansible	Docker socket	Container orchestration
kubernetes-mcp	kubeconfig	Cluster management
ssh-mcp	SSH keys	Remote server access

Recommendation

Document each privileged service with:

• Required access level
• Business justification
• Mitigating controls
• Audit logging requirements

---

4. Default Credential Pattern (LOW)

Severity: LOW Affected Service: ghost-mcp CWE: CWE-1188 (Initialization with Hard-Coded Network Resource Configuration)

Description

Ghost MCP service shows a placeholder credential pattern:

# Line 224
environment:
  - GHOST_API_KEY=${GHOST_API_KEY:-your-api-key-here}

While this is a placeholder (not a real credential), it establishes a pattern that could lead to:

• Developers committing real credentials
• Default credentials being used in development

Recommendation

• Remove default values entirely
• Fail fast if required variables not set
• Use ${VAR:?VAR must be set} pattern

environment:
  - GHOST_API_KEY=${GHOST_API_KEY:?GHOST_API_KEY must be set}

---

Network Security Analysis

Network Configuration

All services use default Docker networking (bridge). No custom networks defined.

Recommendations

1. Create isolated networks for service groups:

networks:
  mcp-servers:
    driver: bridge
  lsp-servers:
    driver: bridge

2. Limit inter-service communication where not required

---

Resource Limits

Current State

No resource limits defined for any service.

Risk

• Resource exhaustion (memory/CPU)
• Noisy neighbor problems
• Potential denial of service

Recommendation

Add resource constraints:

deploy:
  resources:
    limits:
      cpus: '0.5'
      memory: 512M
    reservations:
      memory: 256M

---

Health Checks

Current State

No health checks defined.

Recommendation

Add health checks for monitoring:

healthcheck:
  test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
  interval: 30s
  timeout: 10s
  retries: 3
  start_period: 40s

---

Positive Findings

1. No host network mode - Services use bridge networking
2. No privileged mode - No containers run with privileged: true
3. Environment variables externalized - Using .env file pattern
4. Read-only mounts where appropriate - kubeconfig mounted read-only
5. Consistent container naming - kneldevstack-aimiddleware- prefix

---

Remediation Priority

Priority	Finding	Effort	Impact
1	Document privileged services	Low	High
2	Add resource limits	Low	Medium
3	Implement socket proxy for Docker access	Medium	High
4	Remove default credential patterns	Low	Low
5	Add health checks	Medium	Medium
6	Create network segmentation	Medium	Medium