[tor-relays] Exploiting firmware

[diffusae]

Which "other parts" do you mean? The GPU blob or Raspbian?
You don't need to use the stock distribution.

On 07.12.2016 23:10, Duncan Guthrie wrote:
> What I was originally getting at was that the parts of the Raspberry Pi
> that are completely proprietary - while there is a free software
> implementation of the GPU blob, most people don't use that, as they are
> on stock Rasbian, which includes all the nasty "other parts" - are a
> great possibility for hijacking, perhaps through malicious code running
> on the GPU, which controls the CPU in several ways. The problem with
> this isn't that this is unique (Intel computers having so much more
> attack surface) but that a flaw in lots of these small computers that
> power a portion of the network means that an exploit in them due to lack
> of diversity would be much more serious.

Better a lots of these small computers than none ...

> The management engine blob is also very serious. One possible mitigation
> might be to run the relays in VMs with good isolation, e.g. Xen on
> recent hardware which has good IOMMU. This makes it much harder to
> exploit the actual software that runs on the ME since the VMs would, in
> theory, have no access to hardware.
> 
> It should be of concern on any hardware that is being used for related
> purposes, I think. However, whether it works out in practice as a
> backdoor that is worth exploiting vs other methods is debatable.
> 
> Regardless, diversity is good.

That's true!

Regards,

> On 07/12/16 20:35, Gumby wrote:
>>   Subject seems to have changed a bit, so not hijacking it.
>> When thinking of any exploitation of firmware - should there be
>> concerns of Intel's Management Engine in the CPU of any relays
>>  running on "home hardware" in any common unused pc or laptop?
>> Should that be a concern on ANY newer Intel hardware?
>>
>> Gumby