Introduction
Web application security is more important than ever. With cyber attacks on the rise, understanding common vulnerabilities is crucial for every developer. This guide covers the OWASP Top 10 and practical mitigation strategies.
1. Injection Attacks
SQL injection remains one of the most dangerous vulnerabilities. Attackers inject malicious code through user inputs.
#
Prevention
``javascript
// Bad: String concatenation
const query = "SELECT * FROM users WHERE id = " + userId;// Good: Parameterized queries
const query = "SELECT * FROM users WHERE id = $1";
await db.query(query, [userId]);
`2. Broken Authentication
Weak authentication mechanisms allow attackers to compromise passwords, keys, or session tokens.
#
Prevention
- Implement multi-factor authentication
- Use secure password hashing (bcrypt, Argon2)
- Implement account lockout after failed attempts
- Use secure session management
3. Cross-Site Scripting (XSS)
XSS occurs when applications include untrusted data in web pages without proper validation.
#
Prevention
javascript
// Always sanitize user input
import DOMPurify from 'dompurify';
const clean = DOMPurify.sanitize(userInput);// Use Content Security Policy headers
Content-Security-Policy: default-src 'self'
`4. Insecure Direct Object References
Occurs when applications expose internal implementation objects to users.
#
Prevention
- Implement proper access controls
- Use indirect references (UUIDs instead of sequential IDs)
- Validate user permissions for every request
5. Security Misconfiguration
Default configurations, incomplete setups, and open cloud storage are common issues.
#
Prevention
- Remove default credentials
- Disable unnecessary features
- Keep software updated
- Implement security headers
6. Sensitive Data Exposure
Insufficient protection of sensitive data like passwords, credit cards, or personal information.
#
Prevention
- Encrypt data at rest and in transit
- Use strong encryption algorithms (AES-256)
- Implement proper key management
- Minimize data collection
7. Cross-Site Request Forgery (CSRF)
Forces users to execute unwanted actions on applications where they're authenticated.
#
Prevention
javascript
// Use CSRF tokens
app.use(csrf());// Include token in forms
``8. Using Components with Known Vulnerabilities
Using outdated libraries with known security issues.
#
Prevention
- Regularly audit dependencies
- Use tools like npm audit or Snyk
- Subscribe to security advisories
- Implement automated dependency updates
9. Insufficient Logging & Monitoring
Without proper logging, attacks may go undetected for months.
#
Prevention
- Log authentication attempts
- Monitor for suspicious patterns
- Implement real-time alerting
- Retain logs for investigation
10. Server-Side Request Forgery (SSRF)
Attackers abuse server functionality to access internal resources.
#
Prevention
- Validate and sanitize user-supplied URLs
- Use allowlists for external resources
- Disable unnecessary URL schemes
- Implement network segmentation
Conclusion
Security is not a one-time task but an ongoing process. Regular security audits, penetration testing, and staying updated on the latest threats are essential for maintaining a secure application.
