As much as...
... This is interesting to note, given that there are virtually no 747s in passenger service anymore, and those in freight service tend to not have IFE systems, this is a fluff piece that's well... pointless.
Nevermind the 'bait and switch' here... "How we got persistent shell access on a 747" - No, you got persistent shell access to the IFE, not the 747. At least on the 747, there were distinct physically separate networks. Boeing only switched to VLAN-based access on the 787 (or was it the 777?) so this is rubbish.
Oh, and for God's sake, please fact check not only your own work but also the work of the provider of the fluff piece, i.e. Pen Test Partners. Searching for "APU location 747" would show you instantly where it is, the tail end, not the nose end.
Call me grouchy, but when it comes to accuracy (and past rubbish fluff pieces about network security on planes), I'll be pretty pedantic. So, fix it please.
Biting the hand that feeds IT
