Web Application Penetration Testing Methodology
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Introduction to Web Application Penetration Testing
Web application penetration testing is a systematic process of identifying and exploiting security vulnerabilities in web applications. This methodology provides a structured approach to ensure comprehensive coverage and consistent results.
Pre-Engagement Activities
Scoping and Planning
- Define clear test boundaries and objectives
- Establish testing timeframes and authorized activities
- Document emergency contacts and escalation procedures
- Obtain proper written authorization
- Clarify testing limitations and constraints
Information Gathering
- Review available documentation
- Understand application architecture
- Identify key functionality and business logic
- Determine appropriate testing tools and techniques
- Create testing accounts if needed
Reconnaissance Phase
Passive Information Gathering
- Domain and subdomain enumeration
- Historical data analysis (Wayback Machine)
- Technology stack identification
- Public data source review (GitHub, Pastebin, etc.)
- Search engine discovery
Active Information Gathering
- Network port scanning
- Service enumeration
- Web server fingerprinting
- Framework identification
- Directory and file enumeration
- Virtual host discovery
Mapping the Application
Functionality Enumeration
- Identify all application features
- Map user roles and permissions
- Document authentication mechanisms
- Catalog input fields and parameters
- Identify server-side technologies
Content Discovery
- Directory brute forcing
- Analyze robots.txt and sitemap.xml
- Discover hidden endpoints
- Identify API endpoints
- Map client-side code (JavaScript)
Vulnerability Assessment
Authentication Testing
- Password policy analysis
- Authentication bypass attempts
- Multi-factor authentication review
- Session management testing
- Account lockout testing
Authorization Testing
- Vertical privilege escalation
- Horizontal privilege escalation
- Insecure direct object references
- Missing function-level access control
- Authorization bypass techniques
Input Validation Testing
- Cross-site scripting (XSS)
- SQL injection
- Command injection
- XML external entity (XXE)
- Server-side request forgery (SSRF)
- File upload vulnerabilities
- Cross-site request forgery (CSRF)
Business Logic Testing
- Workflow bypass attempts
- Business rule testing
- Integrity check validation
- Time-based attack scenarios
- Feature abuse and misuse cases
Exploitation Phase
Vulnerability Validation
- Proof-of-concept development
- Exploitation depth determination
- Impact assessment
- Chaining vulnerabilities
- Privilege escalation attempts
Post-Exploitation Activities
- Data access assessment
- Lateral movement possibilities
- Persistence evaluation
- Evidence collection
- Clean-up procedures
Reporting
Documentation Requirements
- Executive summary
- Technical findings with severity ratings
- Reproduction steps with screenshots
- Impact assessment
- Remediation recommendations
- Risk-based prioritization
Severity Classification
- Critical: Direct system compromise
- High: Significant data exposure or functionality compromise
- Medium: Limited data exposure or security control bypass
- Low: Minor security issues with limited impact
- Informational: Best practice recommendations
Tools and Resources
Recommended Testing Tools
- Web Proxies: Burp Suite, OWASP ZAP
- Scanners: Nikto, Nuclei
- Reconnaissance: Amass, Subfinder
- Exploitation: Metasploit, SQLmap
- Custom Scripts: Python, Ruby
Testing Frameworks
- OWASP Web Security Testing Guide
- OWASP Application Security Verification Standard
- NIST SP 800-115
- PTES (Penetration Testing Execution Standard)
Additional Considerations
Legal and Ethical Considerations
- Stay within authorized scope
- Protect sensitive data discovered during testing
- Avoid denial of service conditions
- Report critical findings immediately
- Maintain confidentiality of results
Modern Application Challenges
- Single-page application testing techniques
- API security testing approaches
- Mobile application integration points
- Cloud-native application considerations
- Microservices architecture testing