The $_internalIndexKey aggregation expression can be used by any authenticated user to crash a MongoDB server (mongod). The expression fails to handle compound wildcard index specifications, triggering an internal consistency check that aborts the server process. The user must be able to run an aggregation pipeline.
Weakness
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mongodb | Mongodb | 7.0.0 (including) | 7.0.39 (excluding) |
| Mongodb | Mongodb | 8.0.0 (including) | 8.0.28 (excluding) |
| Mongodb | Mongodb | 8.2.0 (including) | 8.2.12 (excluding) |
| Mongodb | Mongodb | 8.3.0 (including) | 8.3.7 (excluding) |
Extended Description
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service. For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.