A security issue exists in MongoDB's 2dsphere index key generation that can cause a server crash due to a null pointer dereference. When a specially crafted GeoJSON document is inserted into a collection with a 2dsphere index, an inconsistency in geometry parsing can leave an internal object in an invalid, partially initialized state. During subsequent index key generation, access to this improperly initialized object results in a null pointer dereference that terminates the mongod process. An authenticated user with write access can use this to cause a denial of service.