hunt-business-logic

To find business logic vulnerabilities in checkout flows, you test for coupon race conditions, price tampering, negative-quantity manipulation, and price-based TOCTOU across payment and SaaS platforms to demonstrate real-world revenue impact.

A price-based TOCTOU vulnerability occurs when an archived price is trusted during checkout without server-side validation, allowing attackers to exploit timing differences between adding items and finalizing the transaction to alter the final price.

Safely reproduce coupon race conditions by applying an end-to-end hunting methodology that tests discount application workflows responsibly, quantifies impact through real-world case references, and prioritizes remediation guidance for disclosure.

Yes, this approach detects negative-quantity price manipulation by applying end-to-end testing to price calculations and checkout flows across SaaS and ecommerce platforms to identify decimal overflow and fraction price-field issues.

Yes, business logic vulnerability hunting requires testing server-side validation of pricing to verify if checkout flows robustly check price calculations, discount applications, and refund paths against client-side price trust and tampering.

Testing business logic flaws requires careful consideration of responsible disclosure and risk assessment limitations, as reproducing chains like coupon races or price tampering must be done safely to avoid causing actual revenue loss or unauthorized behavior.