JS Prototype Pollution

This exercise covers how to exploit Prototype Pollution against a JavaScript application

< 1 Hr.
Brown Badge


The course explores prototype pollution, a vulnerability in JavaScript applications that allows an attacker to define arbitrary attributes shared by every object in the application. The concept is illustrated through a well-known example involving the Lodash library. The course demonstrates how to exploit this issue by adding an element `__proto__` in a JSON request, enabling you to set necessary attributes and alter the application's behavior.

A detailed step-by-step guide is provided, starting with a basic JavaScript console demonstration to explain the concept of prototype pollution. The course then transitions to a practical challenge where the merge function is exploited to inject attributes into the application's prototype. This exercise showcases how such vulnerabilities can be leveraged to access restricted parts of an application and emphasizes the potential risk of Denial of Service (DoS) in real-world scenarios.

Want to learn more? Get started with PentesterLab Pro! GO PRO