This document outlines security considerations for the FAQ Generator application.

This is a demonstration application designed to showcase the capabilities of the GitHub Copilot SDK. As such, it includes basic security features but is not production-ready without additional hardening.

Status: Not implemented
Risk Level: Medium
Impact: Without rate limiting, the application is vulnerable to:

• Denial of Service (DoS) attacks
• Resource exhaustion from excessive file uploads
• API abuse through rapid requests

Recommendation for Production:

// Install express-rate-limit
npm install express-rate-limit

// Add to server.ts
import rateLimit from 'express-rate-limit';

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // Limit each IP to 100 requests per windowMs
  message: 'Too many requests, please try again later.'
});

app.use('/api/', limiter);

Status: Basic validation implemented
Current Implementation:

• URL format validation
• File type validation (by extension)
• File size limits (10MB)

Recommendations for Production:

• Add content-type header validation
• Implement file signature (magic number) validation
• Add URL allowlist/blocklist functionality
• Validate Excel file structure before processing
• Implement image content scanning

Status: ✅ All critical vulnerabilities resolved
Recent Updates:

• Upgraded multer from 1.4.5-lts.2 to 2.0.2 (fixes 4 DoS vulnerabilities)
• Replaced xlsx with exceljs (eliminates Prototype Pollution and ReDoS vulnerabilities)
• Verified with npm audit: 0 vulnerabilities found

Recommendations:

• Regularly run npm audit and update dependencies
• Use Dependabot or similar tools for automated security updates
• Review dependency changelogs before updating

Status: Basic error handling implemented
Considerations:

• Error messages may expose internal system information
• Stack traces should not be sent to clients in production

Recommendations for Production:

// Don't expose detailed errors to clients
catch (error) {
  console.error('Detailed error:', error);
  res.status(500).json({ 
    error: 'An error occurred processing your request' 
  });
}

Status: Not implemented
Risk Level: High for production use
Impact: Anyone can access the application and consume resources

Recommendations for Production:

• Implement user authentication (OAuth, JWT, etc.)
• Add API key requirements for programmatic access
• Implement usage quotas per user
• Add role-based access control if needed

Current Behavior:

• Uploaded files are temporarily stored on disk
• Files are deleted after processing
• No data is persisted beyond the request lifecycle

Considerations:

• URLs may contain sensitive information
• Excel files may contain private data
• Images may contain personal information

Recommendations:

• Add data encryption at rest
• Implement secure file deletion (overwrite before delete)
• Add privacy policy and terms of service
• Consider GDPR/CCPA compliance requirements
• Implement audit logging for compliance

Status: Not enforced
Risk Level: High for production use
Impact: Data transmitted in plain text can be intercepted

Recommendations for Production:

• Deploy behind a reverse proxy (nginx, Apache)
• Use Let's Encrypt for free SSL certificates
• Enforce HTTPS redirects
• Implement HSTS headers

Status: Not configured
Recommendations:

import cors from 'cors';

app.use(cors({
  origin: process.env.ALLOWED_ORIGINS?.split(',') || '*',
  methods: ['GET', 'POST'],
  credentials: true
}));

Status: Not implemented
Recommendations:

import helmet from 'helmet';

app.use(helmet.contentSecurityPolicy({
  directives: {
    defaultSrc: ["'self'"],
    styleSrc: ["'self'", "'unsafe-inline'"],
    scriptSrc: ["'self'"],
    imgSrc: ["'self'", "data:"]
  }
}));

1. Environment Variables: Store sensitive configuration in environment variables, never in code
2. Secrets Management: Use tools like HashiCorp Vault, AWS Secrets Manager, or Azure Key Vault
3. Logging: Implement comprehensive logging with tools like Winston or Bunyan
4. Monitoring: Set up monitoring and alerting for suspicious activity
5. Regular Updates: Keep all dependencies up-to-date
6. Security Headers: Use helmet.js to set secure HTTP headers
7. Input Sanitization: Sanitize all user inputs before processing
8. Output Encoding: Encode output to prevent XSS attacks
9. File System Access: Limit file system access and use sandboxing where possible
10. Regular Security Audits: Conduct periodic security reviews and penetration testing

This application is provided as-is for demonstration purposes. The authors are not responsible for any security issues that may arise from deployment or modification of this code. Always conduct a thorough security review before deploying any application to production.

If you discover a security vulnerability in this demonstration code, please report it by:

1. Opening a private security advisory on GitHub
2. Not publicly disclosing the issue until it has been addressed
3. Providing detailed information about the vulnerability

• OWASP Top 10
• Node.js Security Best Practices
• Express Security Best Practices
• GitHub Copilot SDK Security