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Re: Re: CVE Request: Linux kernel crash of OHCI when plugging in malicious USB devices


From: Willy Tarreau <w () 1wt eu>
Date: Thu, 18 Aug 2016 21:50:24 +0200

On Thu, Aug 18, 2016 at 08:16:27PM +0200, Adam Maris wrote:
Attacker doesn't necessarily need to have physical access to USB port. He
can somehow
hand USB off to the victim that will with good intentions stick it to his
USB port, unexpectedly
causing kernel panic. Difference is that one probably wouldn't pour glue or
corrosive liquid
into his USB port believing that nothing bad will happen.

Well, it happened to me when I was a kid, with a PS/2 port. I handed off
a device to someone of trust to connect to the PS/2 port and parallel port.
(PS/2 to pick the +5V). I wired it wrong and the motherboard died, as
amazing as it seems and the person didn't find it fun as it was not his PC.

So yes it can be done even without suspecting. It's easy to do whatever you
want using a USB stick. You can use the 3W it provides to charge a 300V
capacitor and discharge it on the D+/D- to test the clamping diodes
robustness, etc...

Thus I don't think either that something "only causing a panic" deserves
a CVE. It needs to be fixed however, for sure!

Regards,
Willy


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