So from the reading I did a while ago on ADS-B, the new kinda-mesh-network-y protocol for planes to report their position to air traffic control, there is basically no security baked into the protocol.
Nothing's encrypted, nothing's signed. Packets may be passed on peer-to-peer to allow traffic data to get around gaps in ground station reception, with no way to authenticate that it came from the original plane untampered-with.
@brion its been a potential vuln since 2012 but nothing too bad has happened - there are various other ways of working out if the 1900 MHz signal is from aircrafts or someone with a transmitter on the ground (unsurprisingly the aviation authorities and the Air Forces won't say exactly what these are or how often the data is audited!)
https://youtube.com/watch?v=CXv1j3GbgLk
The network ID numbers (equivalent of an IP address or phone number) are publicly available, so an attacker could trivially inject fake traffic pretending to be real planes.
I dunno, I worry about this shit.