Mongoose: Prototype pollution in mongoose update casting via __proto__-prefixed dotted path (Schema._getSchema/path getter) — mongoose
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')Impact
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__"
Patches
Has the problem been patched? What versions should users upgrade to?
9.7.2, 8.24.1. 7.8.10, 6.13.10
Workarounds
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
References
Are there any links users can visit to find out more?
- https://github.com/Automattic/mongoose/commit/f494b8430f9097fc70446d6949c8a42a27518e0b
- https://github.com/Automattic/mongoose/pull/16230
- https://github.com/Automattic/mongoose/releases/tag/6.13.10
- https://github.com/Automattic/mongoose/releases/tag/7.8.10
- https://github.com/Automattic/mongoose/releases/tag/8.24.1
- https://github.com/Automattic/mongoose/releases/tag/9.7.2
- https://github.com/Automattic/mongoose/security/advisories/GHSA-664h-wqgq-64gw
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