Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <201102221731.05213.thomas@suse.de>
Date: Tue, 22 Feb 2011 17:31:05 +0100
From: Thomas Biege <thomas@...e.de>
To: oss-security@...ts.openwall.com
Subject: gdm PostLogin script executes scripts as user gdm

Hello oss-security,

should we consider this as a vulnerability?
https://bugzilla.gnome.org/show_bug.cgi?id=602403

cite:
------------------------------------------------------------------------------
ericlesoll [reporter] 2009-11-19 13:00:11 UTC

on Ubuntu Karmic Koala and Fedora 12
After a fresh install on some machines and update from Jaunty on another one,
we can't catch $USER $USERNAME $LOGNAME
from /etc/gdm/PostLogin/Default, we get "gdm" for all variables instead of real
login name. It was working since 7.04 version.
If in a terminal we run : echo $USER, we get the real login name.

example below :

If I put those 3 lines in /etc/gdm/PostLogin/Default:

echo $USER > /tmp/aaa.txt
echo $USERNAME >> /tmp/aaa.txt
echo $LOGNAME >> /tmp/aaa.txt

after every login I get this result:

$ cat /tmp/aaa.txt
gdm
gdm
gdm

I would expect to get my real login name in those 3 variables instead of "gdm",
which is of no use to take specific action based on which user is logging in.
This was working as expected with at least the 3 previous versions of Ubuntu.
------------------------------------------------------------------------------

Cheers,
Thomas

-- 
 Thomas Biege <thomas@...e.de>, SUSE LINUX, Security Support & Auditing
 SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)
--
  Wer aufhoert besser werden zu wollen, hoert auf gut zu sein.
                            -- Marie von Ebner-Eschenbach

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.