MAVLink Has No Idea Who You Are: Drone Autonomy on an Unauthenticated Link (Part 1)
Every drone fleet I have looked at from a security angle has the same uncomfortable property: the protocol that flies the aircraft was designed for a world where the worst thing that happened to a packet was radio noise. MAVLink, the lingua franca of ArduPilot, PX4, and most commercial companion computers, ships by default with no authentication, no encryption, and no integrity protection beyond a CRC that exists to catch corrupted bytes rather than a deliberate forgery. Anyone who can reach the telemetry radio can ask the vehicle for its parameters. Anyone who can reach it can tell the vehicle to go somewhere else.