Date: Wed, 5 Mar 2008 14:04:08 +0100
From: Nico Golde <oss-security+ml@...lde.de>
To: oss-security@...ts.openwall.com
Subject: Re: request CVE id: insecure handling of DISPLAY in rxvt

Hi Matthieu,
* Matthieu Herrb <matthieu.herrb@...s.fr> [2008-03-05 12:54]:
> Nico Golde wrote:
> >Steve, can I get a CVE id for the following issue in rxvt?
> >"If the DISPLAY environment is not set, rxvt opens an xterm on :0, which on 
> >some headless login-server means anyone can setup an fake X server waiting for 
> >someone loggin in without X forwarding to start rxvt by some mistake or by 
> >some program (thus without even noticing) and getting full shell access to 
> >that other account."
> >This is Debian bug 469296[0].
> >It should be a good idea to check other terminal emulators as well.
> >[0] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=469296
> 
> I don't understand how that's an issue with rxvt. If you "fix" the terminal 
> emulator not to that, yo can still run rxvt -display :0 or env DISPLAY=:0 rxvt.

Sure but what's your point? It still looks different to me 
if the user is forced to enable that or if it's done in the 
background without him noticing it.

> But then  I also don't understant what you mean by "setup an fake X server 
> waiting for someone loggin in..."

He basically meant starting an X server on :0.

Cheers
Nico
-- 
Nico Golde - http://www.ngolde.de - nion@...ber.ccc.de - GPG: 0x73647CFF
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