BadUSB - On Accessories that Turn Evil, by Karsten Nohl + Jakob Lell

Julian H. Stacey jhs at
Mon Oct 6 19:56:44 UTC 2014

Hi freebsd-usb at, 		(I suggest replies to usb@)
cc: freebsd-security at	FYI

Ref. article on BadUSB pan OS (non FreeBSD specific) security loophole
Dated  6 October 2014 Last updated at 15:29 GMT 

I found

Then viewed
	( Which BTW plays nicely inc. sound on FreeBSD-9.2-RELEASE
	+ firefox without any flash installed (certainly no

A fascinating video by Lecturers Karsten Nohl & Jacob Lell at Black Hat 
USA 2014, Run time 44:30 ) 
  (PS for non native English spekers on this global list, dont worry if 
  you find Jacob's accent hard, Karsten resumes for last 3rd, listen on :-)

It seems USB controllers (8041 or so based) can first masquerade
one device, then pause & masquerade another device type.  This is
an OS independent security list. Lecturers includes both demo of
an MS to Linux contamination, & consideration of other scenarios.
A predominant USB controller manufacturer in Taipei was not happy.

The lecturers didn't discuss MS or Linux or Android smart phone
protection schemes (except to allude to the danger of someone saying
"Can I plug in my smart phone to your PC to charge it ?".

It can't be ignored as a smart phone exploit: the demo wasn't with a
smart phone but a `dumb' stick. 

One can't get some protection by checking for sernum connecting, as devd shows:
- my USB to PS2 adapter (vendor=0x04b4 product=0x8081) emits sernum=""
- my real USB "Havit" keyboard (vendor=0x1241 product=0x1203) emits sernum=""

For FreeBSD,
  I guess for serious security, every new device that is connected
  & recognised by /sbin/devd should in future be personaly authorised
  by a human !  One can no longer trust what reports itself to be
  eg a keyboard to actually Be a keyboard, etc.

  /usr/src/etc/devd/*.conf & my own .conf do Not meet that awkward
  security requirement... yet. I guess we'll need a couple of hooks
  that support Yes/No, one from cli & one for within X11.

There's no security warning section in

Julian Stacey, BSD Linux Unix'78 C Sys Eng Consultant Munich
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