Web applications are the most common target for attackers. Understanding the OWASP Top 10 and how to test for these vulnerabilities is essential for any security professional.
The OWASP Top 10 (2024)
A01: Broken Access Control
Access control enforces policy such that users cannot act outside of their intended permissions. Failures typically lead to unauthorized information disclosure, modification, or destruction of data.
Testing: Try accessing resources without authentication. Modify user IDs in URLs. Test for IDOR (Insecure Direct Object Reference) vulnerabilities.
A02: Cryptographic Failures
Previously known as Sensitive Data Exposure. This focuses on failures related to cryptography which often lead to exposure of sensitive data.
Testing: Check for data transmitted in cleartext. Verify strong encryption algorithms are used. Look for hardcoded keys or weak random number generators.
A03: Injection
SQL injection, NoSQL injection, OS command injection, and LDAP injection occur when untrusted data is sent to an interpreter as part of a command or query.
Testing: Insert SQL syntax in input fields. Test for command injection in parameters. Use automated tools like SQLmap.
A04: Insecure Design
A new category focusing on risks related to design and architectural flaws. Secure coding practices cannot fix an insecure design.
Testing: Review threat models. Check for missing rate limiting, business logic flaws, and trust boundary violations.
A05: Security Misconfiguration
Missing security hardening, unnecessary features enabled, default credentials, overly permissive CORS, verbose error messages.
Testing: Check default credentials. Look for directory listing. Verify security headers. Check for debug modes in production.
Testing Tools
- Burp Suite: The industry standard web vulnerability scanner
- OWASP ZAP: Free, open-source alternative to Burp Suite
- Nikto: Web server scanner
- SQLmap: Automated SQL injection tool
- Postman: API testing tool
Practice Environments
- DVWA: Damn Vulnerable Web Application
- WebGoat: OWASP's teaching platform
- HackTheBox: Online penetration testing labs
- PortSwigger Web Security Academy: Free training labs