[antmldr]

Yep, hit the nail on the head.

Thing is, if you're able to inject un-authorised code into the FMS, chances are you have bigger concerns than a single aircraft getting hijacked.

It's the equivalent of saying "If I had access to a bank's mainframe and network infrastructure, I could steal millions of dollars with an Android App." Sure you could, but is the problem the fact you can do it with an Android App, or the fact you were able to inject the code in the first place?

[malkarouri]

Exactly. If I have that much capabilities I would buy the airline. It seems neater.