In OpenAirInterface V2.2.0 AMF, Out of sequence messages causes incorrect state transition during UE registration procedure. This allows authentication to be bypassed completely. If a SecurityModeComplete message is sent after InitialUERegistration, a registration reject is received followed by a registration accept! This leads the UE to be registered without proper authentication.
OpenAirInterface V2.2.0 AMF crashes when it fails to decode the message. Not all decode failures result in a crash. But the crash is consistent for particular inputs. An example input in hex stream is 80 00 00 0E 00 00 01 00 0F 80 02 02 40 00 58 00 01 88.