The Claude Code Telegram Bot implements a defense-in-depth security model with multiple layers:

• User Whitelist: Only pre-approved Telegram user IDs can access the bot
• Token-Based Auth: Optional token-based authentication for additional security
• Session Management: Secure session handling with timeout and cleanup

• Approved Directory: All operations confined to a pre-configured directory tree
• Path Validation: Prevents directory traversal attacks (../../../etc/passwd)
• Permission Checks: Validates file system permissions before operations

• Command Sanitization: All user inputs sanitized to prevent injection attacks
• File Type Validation: Only allowed file types can be uploaded
• Path Sanitization: Removes dangerous characters and patterns (;, &&, $(), ..)
• Secret File Protection: Blocks access to .env, .ssh, id_rsa, .pem files

• Request Rate Limiting: Token bucket algorithm prevents abuse with configurable limits
• Cost-Based Limiting: Tracks and limits Claude usage costs per user
• Burst Protection: Configurable burst capacity prevents spike attacks

• Authentication Events: All login attempts and auth failures logged
• Command Execution: All commands and file operations logged
• Security Violations: Path traversal attempts, injection attempts, and other violations logged
• Risk Assessment: Automatic severity classification for security events

• GitHub HMAC-SHA256: Webhook payloads verified against X-Hub-Signature-256 header using a shared secret
• Generic Bearer Token: Non-GitHub providers authenticated via Authorization: Bearer <token> header
• Deduplication: Atomic INSERT OR IGNORE on delivery ID prevents replay attacks
• Event Security Middleware: Validates webhook events before handler processing

All planned security features are implemented and active:

• Multi-provider authentication system (whitelist + token)
• Rate limiting with token bucket algorithm (request and cost-based)
• Input validation with path traversal, command injection, and zip bomb protection
• Directory isolation with approved directory boundaries
• Security audit logging with risk assessment and event tracking
• Bot middleware framework (auth, rate limit, security, burst protection)
• Webhook signature verification (GitHub HMAC-SHA256, generic Bearer token)
• Event security middleware for webhook and scheduled event validation
• Configuration security via Pydantic validators and SecretStr

# Base directory for all operations (CRITICAL)
APPROVED_DIRECTORY=/path/to/approved/projects

# User access control
ALLOWED_USERS=123456789,987654321  # Telegram user IDs

# Optional: Token-based authentication
ENABLE_TOKEN_AUTH=true
AUTH_TOKEN_SECRET=your-secret-here  # Generate with: openssl rand -hex 32

# GitHub webhook signature verification
GITHUB_WEBHOOK_SECRET=your-github-webhook-secret

# Generic webhook Bearer token
WEBHOOK_API_SECRET=your-api-secret

# API server (required for webhooks)
ENABLE_API_SERVER=true
API_SERVER_PORT=8080

# Strict rate limiting for production
RATE_LIMIT_REQUESTS=5
RATE_LIMIT_WINDOW=60
RATE_LIMIT_BURST=10

# Cost controls
CLAUDE_MAX_COST_PER_USER=5.0

# Security features
ENABLE_TELEMETRY=true  # For security monitoring
LOG_LEVEL=INFO         # Capture security events

# Environment
ENVIRONMENT=production  # Enables strict security defaults

1. Directory Configuration

   # Use minimal necessary permissions
   chmod 755 /path/to/approved/projects
   
   # Avoid sensitive directories
   # Don't use: /, /home, /etc, /var
   # Use: /home/user/projects, /opt/bot-projects

2. Token Management

   # Generate secure secrets
   openssl rand -hex 32
   
   # Store in environment, never in code
   export AUTH_TOKEN_SECRET="generated-secret"
   export GITHUB_WEBHOOK_SECRET="generated-secret"
   export WEBHOOK_API_SECRET="generated-secret"

3. User Management

   # Get Telegram User ID: message @userinfobot
   # Add to whitelist
   export ALLOWED_USERS="123456789,987654321"

4. Monitoring

   # Enable logging and monitoring
   export LOG_LEVEL=INFO
   export ENABLE_TELEMETRY=true
   
   # Monitor logs for security events
   tail -f bot.log | grep -i "security\|auth\|violation"

1. Never Commit Secrets -- use .gitignore for .env, *.key, *.pem
2. Use Type Safety -- all functions must have type hints (mypy --strict)
3. Validate All Inputs -- use SecurityValidator for user-provided paths and commands
4. Log Security Events -- use structlog with violation_type and user_id context

1. Directory Traversal (High Priority) -- path traversal, symlink attacks
2. Command Injection (High Priority) -- shell injection, env var injection
3. Unauthorized Access (Medium Priority) -- non-whitelisted users, token replay
4. Resource Abuse (Medium Priority) -- rate limit bypass, cost limit violations
5. Webhook Forgery (Medium Priority) -- unsigned payloads, replay attacks
6. Information Disclosure (Low Priority) -- sensitive file exposure, error leakage

• Network-level attacks (handled by hosting infrastructure)
• Telegram API vulnerabilities (handled by Telegram)
• Host OS security (handled by system administration)

Do not create public GitHub issues for security vulnerabilities.

For security issues, please email: [Insert security contact email]

Include: description, steps to reproduce, potential impact, and suggested mitigation.

1. Acknowledgment within 48 hours
2. Initial assessment within 1 week
3. Fix development as soon as possible
4. Security advisory published after fix

• APPROVED_DIRECTORY properly configured and restricted
• ALLOWED_USERS whitelist configured
• Rate limiting enabled and configured
• Logging enabled and monitored
• Authentication tokens properly secured
• GITHUB_WEBHOOK_SECRET set (if using GitHub webhooks)
• WEBHOOK_API_SECRET set (if using generic webhooks)
• API server behind reverse proxy with TLS (if enabled)
• Environment variables properly configured
• File permissions properly set
• Network access properly restricted
• All dependencies updated to latest secure versions