--- title: "Web Application Security Checklist: 25 Essential Items" publishedAt: "2024-07-01" author: "Elena Vance" category: "Technology" --- Security vulnerabilities can destroy user trust and sink companies. We have compiled the essential security items every web application should address before going to production.
Authentication Security
Strong authentication is your first line of defense.
1. Password Hashing
Never store passwords in plain text. Use bcrypt, scrypt, or Argon2 with appropriate cost factors. SHA-256 is not sufficient for password hashing.
2. Multi-Factor Authentication
Offer MFA for all users and require it for administrative accounts. TOTP apps like Google Authenticator are more secure than SMS.
3. Session Management
Use secure, HTTP-only cookies with appropriate expiration. Implement session invalidation on password change and provide users with active session visibility.
4. Brute Force Protection
Rate limit login attempts by IP and account. Implement progressive delays or temporary lockouts after failed attempts.
5. Password Requirements
Enforce minimum length (12+ characters) but avoid arbitrary complexity rules. Check passwords against known breach databases.
Data Protection
Protecting user data requires encryption and access controls.
6. Encryption in Transit
Use TLS 1.3 for all connections. Redirect HTTP to HTTPS and implement HSTS with a long max-age.
7. Encryption at Rest
Encrypt sensitive data in your database using AES-256. Manage encryption keys separately from encrypted data.
8. Data Minimization
Only collect data you actually need. Delete data when it is no longer required for its original purpose.
9. PII Handling
Identify all personally identifiable information in your system. Apply appropriate access controls and audit logging.
10. Backup Encryption
Encrypt all backups with keys stored separately from the backup data. Test restoration procedures regularly.
Input Validation
Never trust user input.
11. SQL Injection Prevention
Use parameterized queries or prepared statements for all database operations. Never concatenate user input into SQL strings.
12. XSS Prevention
Encode output appropriate to context (HTML, JavaScript, URL). Use Content Security Policy headers to restrict script sources.
13. CSRF Protection
Implement anti-CSRF tokens for state-changing operations. Use SameSite cookie attributes.
14. File Upload Security
Validate file types by content, not just extension. Store uploaded files outside the web root and serve through a separate domain.
15. Input Sanitization
Validate and sanitize all user input on the server side. Client-side validation is for UX, not security.
Infrastructure Security
Your infrastructure is part of your attack surface.
16. Least Privilege Access
Grant minimum necessary permissions to all accounts and services. Use separate credentials for development and production.
17. Secrets Management
Never commit secrets to version control. Use environment variables or dedicated secrets management services.
18. Dependency Scanning
Regularly scan dependencies for known vulnerabilities. Automate updates where possible and review security advisories.
19. Container Security
Use minimal base images and run containers as non-root users. Scan images for vulnerabilities before deployment.
20. Network Segmentation
Isolate production environments from development. Use private networks for database and internal service communication.
Monitoring and Response
Detection and response are as important as prevention.
21. Security Logging
Log authentication events, authorization failures, and administrative actions. Ensure logs cannot be tampered with.
22. Intrusion Detection
Monitor for suspicious patterns like unusual login locations, privilege escalation attempts, and data exfiltration.
23. Incident Response Plan
Document procedures for responding to security incidents. Define roles, communication channels, and escalation paths.
24. Regular Audits
Conduct periodic security reviews and penetration testing. Address findings promptly and track remediation.
25. Vulnerability Disclosure
Provide a clear channel for security researchers to report vulnerabilities. Respond promptly and fix issues responsibly.
Implementation Priority
If you are just getting started with security, prioritize in this order: authentication basics, input validation, encryption in transit, logging, then work through the rest systematically. Security is not a one-time project but an ongoing commitment.
