[Full-disclosure] Linux big bang theory....

[Andrew Farmer]

On 13 May 07, at 21:24, Tremaine Lea wrote:
> This might be a bit hard for you to understand, but no OS is  
> impossible to break.
>
> If you think that's the case with OSX, you haven't been keeping up  
> very well at all.
>
> And before you get your knickers in a bunch, *I* use OSX.

Yep. All that I was pointing out was that this script happens to  
break under OS X, because it makes assumptions that aren't true  
outside a Linux system. This doesn't mean that it couldn't be  
modified to work correctly, though.

This script really doesn't prove anything, though. All it shows is  
that a compromised machine can be difficult to impossible to clean  
properly - which has been known for a *long* time. Ken Thompson  
discussed a much cleverer one in "Trusting Trust". It's also worth  
noting that this is in no way specific to UNIX systems. It's simply  
an unalterable fact that, once an attacker has had full access to the  
machine, it's possible for them to make changes which will allow them  
reentry at a later date.