4 ms·
Coincidentally, I was updating HP LaserJet firmware last week and when the update tool was running, I was surprised to see it sent the firmware as a 'normal' jo
by jbronn 15y ago
Coincidentally, I was updating HP LaserJet firmware last week and when the update tool was running, I was surprised to see it sent the firmware as a 'normal' job to the printer. My guess is this is how the exploit works -- simply disassemble existing firmware and make sure your malicious job looks like said update.
- chris_dcosta 15y agoI know I commented earlier, but I slept on it last night and I realised I'd already hacked printers in this way and got paid to do it - I'd just completely forgotten. Years ago, I was working for well known lighting manufacturer and CD inventor you know who I mean... they had a SAP system that did not have a printer driver for the thermal printers they were using on all their products. I'd been using a bizarre pseudo mark-up language called SAPScript on a couple of projects and discovered quite by accident ;) that you could encode printer commands directly into the SAPscript. Exactly the same principle I guess as including php code in HTML. At some point the machine knows to parse the code not print it. I could get it to do some mad printed stuff as long as you could controll the variables that you passed to the script. I never tried the burn baby burn effect though. I was too nice.