00 — Overview

Prototype Pollution

JavaScript's prototype chain is its superpower — and its biggest footgun. Pollute Object.prototype and every object in the application inherits your injected properties. From filter bypass to RCE.

Intermediate·45 min·5 tasks
// By the end of this module
→Explain the JavaScript prototype chain and how __proto__ modifies it
→Identify client-side prototype pollution via URL parameters and merge utilities
→Demonstrate server-side prototype pollution leading to isAdmin bypass
→Understand how prototype pollution chains into RCE via execPath poisoning
→Freeze Object.prototype and use Object.create(null) to prevent pollution
// Prerequisites
Complete these before starting this module for the best experience.