GHSA-wpg9-53fq-2r8h Mongoose's Improper Sanitization of $nor in sanitizeFilter May Allow NoSQL Injection

• npm mongoose: < 6.13.9 → fixed in 6.13.9 • npm mongoose: >= 7.0.0, < 7.8.9 → fixed in 7.8.9 • npm mongoose: >= 8.0.0, < 8.22.1 → fixed in 8.22.1 • npm mongoose: >= 9.0.0, < 9.1.6 → fixed in 9.1.6

Impact This vulnerability allows bypassing Mongoose’s sanitizeFilter query sanitization mechanism via the `$nor` operator. When sanitizeFilter is enabled, Mongoose wraps query operators in `$eq` to neutralize them. However, prior to the fix, `$nor` was not included in the set of logical operators that are recursively sanitized. Because `$nor` accepts an array (like `$and` and `$or`), and arrays do not trigger `hasDollarKeys()`, malicious operators such as `$ne`, `$gt`, or `$regex` could be injected inside a `$nor` clause without being sanitized. This may lead to: • Authentication bypass • Unauthorized data access • Data exfiltration Affected users: Applications that: • Explicitly enable sanitizeFilter • Pass unsanitized user-controlled input directly into query methods (e.g., `Model.findOne(req.body)`) and rely on `sanitizeFilter` to strip out query selectors Applications that validate input schemas, whitelist fields, or avoid passing raw request bodies into queries are not affected. For example, `Model.findOne({ user: req.body.user, pwd: req.body.pwd })` is not affected. Patches Patches have been released for all supported Mongoose release lines: • `^6.13.9` • `^7.8.9` • `^8.22.1` • `^9.1.6` Workarounds Delete `$nor` keys, use an additional schema validation library, or write middleware to strip out `$nor` from query filters. Resources sanitizeFilter documentation: https://mongoosejs.com/docs/api/mongoose.html#Mongoose.prototype.sanitizeFilter() Original blog post on sanitizeFilter: https://thecodebarbarian.com/whats-new-in-mongoose-6-sanitizefilter.html