Re:How I got a Root Shell on a Credit Card Terminal
by fp64 on Sunday June 01, 2025 @12:32PM
(#44152045)
Was my guess as well, maybe it's even possible to use it to flash new keys so the device can be used again?
Now I am curious if I can find a terminal myself, if they are actually getting phased out it might not be too difficult to find a used one...
Re:How I got a Root Shell on a Credit Card Terminal
by stgl on Sunday June 01, 2025 @12:58PM
(#44152235)
I had the same idea, but no, I tried with a second, untampered one and I also got a working shell. So it does not seem to be dependent on the tamper state.
Re:How I got a Root Shell on a Credit Card Terminal
by numpad0 on Monday June 02, 2025 @09:19AM
(#44158558)
wtf? are you saying the shell can be hypothetically drilled for root access without triggering the tamper detection? that'll be ACTUALLY bad...
Re:How I got a Root Shell on a Credit Card Terminal
by fp64 on Monday June 02, 2025 @02:36PM
(#44161696)
I think in the article it was even stated that the port is even accessible without drilling!
Re:How I got a Root Shell on a Credit Card Terminal
by lelanthran on Sunday June 01, 2025 @03:05PM
(#44153056)
> Was my guess as well, maybe it's even possible to use it to flash new keys so the device can be used again?
What keys would you flash them with? Anything encrypted with your "new" keys can't be decrypted on the other end of the transaction anyway, so what would be the point?
Re:How I got a Root Shell on a Credit Card Terminal
by fp64 on Monday June 02, 2025 @02:35PM
(#44161687)
Pretend that I have to pay to watch TV at home? I don't know, sounded fun to me in my head
Plus I meant for the manufacturer to "repair" it. Maybe tamperproof gets triggered if you accidentally drop the device in an unfortunate way
Ie. The system is either in secure mode (with all necessary crypto keys for operation), or it is in insecure mode with a root shell open for debugging and failure analysis, but that transition also deleted the critical private keys.