Re: [Tails-dev] Tails: pcmcia / firewire / etc.

Delete this message

Reply to this message
Autor: Jacob Appelbaum
Data:  
A: tails-dev, Maxim Kammerer
CC: Steve Weis
Assumpte: Re: [Tails-dev] Tails: pcmcia / firewire / etc.
Maxim Kammerer:
> On Sat, Oct 13, 2012 at 1:30 AM, Jacob Appelbaum
> <jacob@???> wrote:
>> I would add Thunderbolt to the list as well:
>> http://www.breaknenter.org/2012/02/adventures-with-daisy-in-thunderbolt-dma-land-hacking-macs-through-the-thunderbolt-interface/
>
>>
> As far as I can see, all these attacks (PCMCIA, ExpressCard,
> Thunderbolt) rely on attaching to a FireWire interface one way or
> another, and then accessing arbitrary memory via DMA. But such
> ability is (or can be) disabled by default in the newer firewire-ohci
> module, as described in "debugging-via-ohci1394.txt", and even
> discussed on the relevant Tails TODO page. So why disable the
> interfaces? Looks like an overkill to me.
>


My understanding is that this assumption doesn't actually pan out in
practice. I've cc'ed Steve who may have some more information to
contribute. As I understand things, he found that as predicted, the
default "it is off" doesn't actually always turn DMA off.

All the best,
Jacob