Web Application Logic

Test for logic flaws and application-specific vulnerabilities that automated scanners miss.

Techniques

| Type | Key Vectors | |------|-------------| | Business Logic | Workflow bypass, price manipulation, feature abuse | | Race Conditions | TOCTOU, limit bypass, double-spend, parallel requests | | Access Control | IDOR, horizontal/vertical privilege escalation, forced browsing | | Cache Poisoning | Unkeyed headers/parameters, fat GET, response splitting | | Cache Deception | Path confusion, static extension tricks, normalization | | Info Disclosure | Error messages, debug endpoints, source code, metadata |

Workflow

1. Map application workflows and business rules
2. Identify state-dependent operations and trust boundaries
3. Test logic assumptions with edge cases and race conditions
4. Verify access control across user roles
5. Document impact with PoC demonstrations

Reference

• reference/business-logic*.md - Business logic testing techniques
• reference/race-conditions*.md - Race condition exploitation
• reference/access-control*.md - Access control bypass methods
• reference/web-cache-poisoning*.md - Cache poisoning techniques
• reference/web-cache-deception*.md - Cache deception attacks
• reference/information-disclosure*.md - Information disclosure testing