# Price Manipulation Vulnerability

> Detects e-commerce logic that trusts client-submitted prices instead of server-side calculation.

- Skill: `zakirkun/price-manipulation-vulnerability` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add zakirkun/price-manipulation-vulnerability`
- Raw SKILL.md: https://api.skillmd.com/api/skills/zakirkun/price-manipulation-vulnerability/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: zakirkun (https://skillmd.com/u/zakirkun)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/zakirkun/price-manipulation-vulnerability

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# Price Manipulation Vulnerability

## Overview
Price manipulation occurs when an application trusts the price submitted by the client (in request body or form fields) instead of calculating it server-side from the product catalog. Attackers can submit negative prices, zero prices, or arbitrarily low prices.

## Remediation
- NEVER trust client-submitted prices
- Always calculate price server-side from the product ID and current catalog
- Validate total = sum of (server_price × quantity) before processing payment