Web applications are the most common target for attackers and therefore a critical focus area for penetration testers. This guide covers the essential methodologies and tools for comprehensive web application security assessments.
Reconnaissance Phase
Before touching the application, gather as much information as possible. Use tools like OWASP Amass, theHarvester, and Google dorking to discover subdomains, technology stacks, and potential entry points.
Mapping the Application
Use Burp Suite's spider or OWASP ZAP's AJAX spider to map the entire application structure. Identify all endpoints, parameters, and input vectors. Pay special attention to API endpoints and single-page application routes.
Automated Scanning
Run automated scanners to identify common vulnerabilities like SQL injection, XSS, and CSRF. Burp Suite's scanner and OWASP ZAP's active scanner provide excellent coverage, but remember they are not a substitute for manual testing.
Manual Testing
The most critical vulnerabilities often require manual verification. Use Burp's Repeater and Intruder to craft custom requests and test business logic flaws. Test for:
- Authentication bypasses
- Authorization flaws
- Business logic vulnerabilities
- Race conditions
- File upload vulnerabilities
- Server-side request forgery (SSRF)
Reporting
Document every finding with clear reproduction steps, impact assessment, and remediation recommendations. Tools like Dradis and Faraday help streamline the reporting process.
Continuous Learning
Web security evolves rapidly. Follow security researchers on Twitter, read disclosed reports on HackerOne and Bugcrowd, and practice on platforms like PortSwigger Web Security Academy and Hack The Box.