The 10-Point Security Checklist for Hardening Clawdbot / MCP (Step-by-Step)

Step 1: Bind to Localhost Only (5 minutes)

The most common mistake: binding services to 0.0.0.0 (all interfaces). Fix this first.

# In your .env or config file:
MCP_HOST=127.0.0.1  # NOT 0.0.0.0
MCP_PORT=8080
ADMIN_HOST=127.0.0.1
ADMIN_PORT=8081

# Verify with:
ss -tlnp | grep 8080
# Should show: 127.0.0.1:8080, NOT 0.0.0.0:8080

Step 2: Add Authentication (15 minutes)

Install and configure Caddy (simplest) or Nginx with basic auth:

# Caddy (auto-TLS, recommended):
# /etc/caddy/Caddyfile
mcp.yourdomain.com {
    basicauth {
        admin $2a$14$your_bcrypt_hash_here
    }
    reverse_proxy 127.0.0.1:8080
}

# Generate password hash:
caddy hash-password --plaintext "your-strong-password"

Step 3: Configure Firewall (10 minutes)

# UFW setup (Ubuntu/Debian)
sudo ufw reset
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow from YOUR_OFFICE_IP to any port 22  # SSH from your IP only
sudo ufw allow 80/tcp   # HTTP (for Let's Encrypt)
sudo ufw allow 443/tcp  # HTTPS
sudo ufw deny 8080/tcp  # Explicitly block direct MCP access
sudo ufw deny 8081/tcp  # Explicitly block direct admin access
sudo ufw enable
sudo ufw status verbose

Step 4: HTTPS/TLS (10 minutes)

# With Caddy (automatic TLS via Let's Encrypt)
sudo apt install -y debian-keyring debian-archive-keyring apt-transport-https curl
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
sudo apt update && sudo apt install caddy
sudo systemctl enable --now caddy

Step 5: Secrets Management (10 minutes)

# Create a .env file with restricted permissions
touch /app/.env
chmod 600 /app/.env
chown appuser:appuser /app/.env

# NEVER commit .env to git
echo ".env" >> .gitignore
echo "*.env" >> .gitignore

# Rotate all secrets now if you've had any exposure:
# 1. Revoke old OpenAI/Anthropic API keys in their dashboards
# 2. Generate new keys
# 3. Update .env
# 4. Restart services

Step 6: Rate Limiting (5 minutes with Caddy)

# In Caddyfile, add rate limiting:
mcp.yourdomain.com {
    rate_limit {
        zone mcp {
            key {remote_host}
            events 100
            window 1m
        }
    }
    basicauth { ... }
    reverse_proxy 127.0.0.1:8080
}

Step 7: Input Validation

In your MCP server configuration, enable input validation for tool parameters:

# clawdbot config.yml
security:
  input_validation:
    enabled: true
    max_message_length: 10000
    block_patterns:
      - "ignore previous instructions"
      - "system:"
      - "SYSTEM:"
      - "/etc/passwd"
      - "../"
    sanitize_html: true

Step 8: Audit Logging

# clawdbot config.yml
logging:
  level: info
  audit:
    enabled: true
    format: json
    output: /var/log/clawdbot/audit.log
    include:
      - tool_calls
      - authentication
      - configuration_changes
  rotate:
    max_size: 100MB
    max_age: 90d
    compress: true

Step 9: Tool Allowlisting

# Only enable tools you actually need
tools:
  enabled:
    - search_web        # If you need web search
    - read_file         # If you need file reading
    # - write_file      # Comment out unless needed
    # - shell_execute   # NEVER enable in production
    # - database_write  # Enable only with restrictions
  
  file_read:
    allowed_paths:
      - "/app/data/"
      - "/app/public/"
    # Explicitly block sensitive paths
    blocked_paths:
      - "/etc/"
      - "/root/"
      - "~/"

Step 10: Monitoring Setup

# Simple monitoring with a cron job + Uptime Kuma or similar
# Check for exposed ports every hour:
0 * * * * ss -tlnp | grep -v 127.0.0.1 | grep -E '(8080|8081|3000)' | mail -s "PORT EXPOSURE ALERT" admin@yourdomain.com

# Check auth log for failures:
0 * * * * grep "authentication failure" /var/log/auth.log | tail -100 | mail -s "Auth failures" admin@yourdomain.com