Get RCE on the gold firmware over the radio

[marksteward]

Just because I think it's an interesting exercise and suspect it's possible. Otherwise, demonstrate reasonably thoroughly that you can or can't do it. Prize to be decided based on style and what I've got available.

Assume you can send signed messages, because that was possible during the event. You'll need an SRF to test it properly, but if you don't have one, send me code (ms7821 on IRC) and I'll have a play.