# Business Logic Vuln

Entry P1 category router for business logic testing.

- Repository: https://github.com/yaklang/hack-skills (2601 stars)
- Category: Testing
- License: MIT
- Last updated: 2026-09-13
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add yaklang/hack-skills --skill business-logic-vuln -g -a claude-code -y`
Codex: `npx skills add yaklang/hack-skills --skill business-logic-vuln -g -a codex -y`
Cursor: `npx skills add yaklang/hack-skills --skill business-logic-vuln -g -a cursor -y`
Gemini CLI: `npx skills add yaklang/hack-skills --skill business-logic-vuln -g -a gemini-cli -y`

## Description

Entry P1 category router for business logic testing. Use when workflow abuse, race conditions, pricing flaws, or multi-step state attacks matter more than parser-level input injection.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Business Logic Router

This is the routing entry point for business-logic and state-machine issues.

## When to Use

- The target involves coupons, inventory, payment, approvals, quotas, invites, trials, or state transitions
- The issue is not parser-level; it is about when checks happen and which business conditions are checked
- You suspect race conditions, workflow bypass, price tampering, negative values, stacked discounts, or multi-step flaws

## Skill Map

- [Business Logic Vulnerabilities](../business-logic-vulnerabilities/SKILL.md)

## Recommended Flow

1. First map key business states and one-time actions
2. Then check for check-then-act windows, sequence dependencies, or missing cross-step authorization
3. If the chain depends on APIs, uploads, or object permissions, return to the corresponding router skill to complete the path

## Related Categories

- [api-sec](../api-sec/SKILL.md)
- [auth-sec](../auth-sec/SKILL.md)
- [file-access-vuln](../file-access-vuln/SKILL.md)