Business logic flaws are vulnerabilities that exist not because of a coding mistake, but because the application trusts its own workflow too much. Instead of exploiting a buffer overflow or injecting code, attackers simply skip steps, repeat actions, or change the order of requests to get outcomes the app never intended. This kind of flaw is common in multi-step processes like account upgrades, order flows, approval chains, and access control checks. Payment bypass is one well-known example, but the same root cause appears across many different features.
Ethical Considerations
Only test systems you own or have written permission to test
Use local labs or bug bounty programs with clear scope
Do not use these techniques against production systems without authorization
