Secure Coding Practices Every Developer Should Know

Security is everyone's responsibility. Here are essential practices for writing secure code.

Input Validation

Never Trust User Input

Validate and sanitize everything:

• Type checking
• Length limits
• Format validation
• Encoding

SQL Injection Prevention

Always use parameterized queries, never string concatenation for SQL.

XSS Prevention

• Escape output
• Content Security Policy
• HTTP-only cookies

Authentication

Password Storage

• Use bcrypt or argon2
• Never store plaintext
• Proper salt handling

Session Management

• Secure session IDs
• Proper expiration
• HTTPS only

Multi-Factor Authentication

Implement MFA for sensitive operations.

Authorization

Principle of Least Privilege

Give minimum necessary permissions.

Access Control

• Check permissions on every request
• Don't rely on client-side checks

Data Protection

Encryption

• TLS for transit
• AES for storage
• Proper key management

Sensitive Data

• Don't log sensitive data
• Mask in UI
• Proper disposal

Common Vulnerabilities (OWASP Top 10)

1. Injection
2. Broken Authentication
3. Sensitive Data Exposure
4. XML External Entities
5. Broken Access Control
6. Security Misconfiguration
7. Cross-Site Scripting
8. Insecure Deserialization
9. Components with Known Vulnerabilities
10. Insufficient Logging

Best Practices

1. Security reviews: Include in code review
2. Dependency scanning: Check for vulnerabilities
3. Penetration testing: Regular testing
4. Security training: Keep team updated

Conclusion

Security is a mindset, not a checklist. Build it into your development process.