Re Kubuntu 64bit, several issues

Tristan Wibberley maihem at
Mon Aug 15 14:57:15 CDT 2005

Daniel Stone wrote:
> On Mon, Aug 15, 2005 at 07:30:18PM +0100, Tristan Wibberley wrote:

>>In that scenario, programs running
>>under my uid do not enter the equation - they would only start the
>>privileged process that sets up the secure environment for password
>>entry. To get my password under that regime, the attacker would have to
>>have root first - or a screwdriver and a crowbar.
> 'they would only start the privileged process that ...'
> And that's where your argument falls down.  How do you know that it's
> actually starting that privileged process, as opposed to some random
> Trojan?

Because the privileged process can write to a socket that only
privileged processes can write to (the kernel sees to that bit). That
write to the socket could tell the X server which window it has
configured, and the X server can then only send keypresses to that
process, so other processes cannot see the password.

Of course, bugs in the privileged programs would leave holes, but those
are bugs and not systematic failures.

>>The debate then, is how best to have Linux stop sudo from being a fairly
>>straightforward target.
> ... not use it at all?

Yes, however sudo is extremely desirable.

> You are welcome to attempt, and I certainly don't discourage you from
> doing so if you feel that it's an effective use of your time, but I do
> not believe that you are able to achieve what you want to while still
> actually using a computer.

Your concern to save me from wasting my time is very much appreciated.

Tristan Wibberley

Opinions expressed are my own and do not necessarily coincide with those
of my employer, etc.

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