[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Bug#158637: marked as done ([dendler@idefense.com: iDEFENSE Security Advisory: Linuxconf locally exploitable buffer overflow])



Your message dated Sun, 11 May 2003 20:40:43 +1000
with message-id <20030511104043.GA28702@regression.cyrius.com>
and subject line Removed
has caused the attached Bug report to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what I am
talking about this indicates a serious mail system misconfiguration
somewhere.  Please contact me immediately.)

Debian bug tracking system administrator
(administrator, Debian Bugs database)

--------------------------------------
Received: (at submit) by bugs.debian.org; 28 Aug 2002 16:31:26 +0000
>From mdz@csh.rit.edu Wed Aug 28 11:31:26 2002
Return-path: <mdz@csh.rit.edu>
Received: from smtp01.mrf.mail.rcn.net [207.172.4.60] 
	by master.debian.org with esmtp (Exim 3.12 1 (Debian))
	id 17k5j4-0000Sr-00; Wed, 28 Aug 2002 11:31:26 -0500
Received: from 209-6-103-23.c3-0.smr-ubr1.sbo-smr.ma.cable.rcn.com ([209.6.103.23] helo=mizar.alcor.net)
	by smtp01.mrf.mail.rcn.net with esmtp (Exim 3.35 #6)
	id 17k5j4-0001si-00
	for submit@bugs.debian.org; Wed, 28 Aug 2002 12:31:26 -0400
Received: from mdz by mizar.alcor.net with local (Exim 3.35 #1 (Debian))
	id 17k5j6-0001Qz-00
	for <submit@bugs.debian.org>; Wed, 28 Aug 2002 12:31:28 -0400
Date: Wed, 28 Aug 2002 12:31:28 -0400
From: Matt Zimmerman <mdz@debian.org>
To: submit@bugs.debian.org
Subject: [dendler@idefense.com: iDEFENSE Security Advisory: Linuxconf locally exploitable buffer overflow]
Message-ID: <20020828163128.GG1310@alcor.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4i
Sender: Matt Zimmerman <mdz@alcor.net>
Delivered-To: submit@bugs.debian.org

Package: linuxconf
Severity: grave
Tags: security

----- Forwarded message from David Endler <dendler@idefense.com> -----

Date: Wed, 28 Aug 2002 11:58:53 -0400
From: "David Endler" <dendler@idefense.com>
To: bugtraq@securityfocus.com, vulnwatch@vulnwatch.org
Subject: iDEFENSE Security Advisory: Linuxconf locally exploitable buffer overflow

 
iDEFENSE Security Advisory 08.28.2002
Linuxconf locally exploitable buffer overflow vulnerability

DESCRIPTION 

A vulnerability exists in linuxconf which if the 
LINUXCONF_LANG environment variable processes at least 964 
bytes of data, a buffer overflow occurs, thereby allowing an 
attacker to modify the return address of the function and 
execute arbitrary code with root permissions.  iDEFENSE has an 
exploit that allows a local user to launch a root shell on Red 
Hat Linux 7.3 by targeting the latest version of linuxconf 
1.28r3. 


ANALYSIS

According to the author of Linuxconf, Jacques Gelinas 
jack@solucorp.qc.ca, "linuxconf picks the variable and uses it 
to format a path using snprintf. This works fine. In fact, the 
receiving buffer is PATH_MAX large so even a 1000 characters 
variable won't overflow it and even if this was the case, 
snprintf would do its work. 

Once the path is formatted, the corresponding file is opened. 
If the file do not exist, an error message is formatted in a 
string. This was the problem and sprintf was used instead of 
snprintf there.

There are two fixes. One is to use snprintf to format error 
message at this place and the other is to look for appropriate 
length for this variable (max 5 characters) immediately when it 
is found."


DETECTION

This vulnerability affects any version of linuxconf 
(essentially 6 years worth of distributions) that is installed 
setuid root.  Generally, the four ways in which this utility 
can be installed setuid are:

1.) Shipped by vendor (Red Hat does not ship linuxconf 
setuid, but Mandrake does as do other linux vendors)
2.) Installed by RPM from the main site 
(http://www.solucorp.qc.ca/linuxconf/) for each particular 
linux OS (installs setuid root by default)
3.) Installed by source code also from main site 
(http://www.solucorp.qc.ca/linuxconf/) but prompts for whether 
to install setuid root 
4.) Installed in ways 1, 2, or 3 and manually set to setuid 
root by the user for added functionality.


WORKAROUND

Remove the setuid bit from the linuxconf binary:

$ chmod u-s /bin/linuxconf


VENDOR RESPONSE

iDEFENSE immediately contacted Jacques Gelinas and he provided 
a source code patch.  iDEFENSE verified that the vulnerability 
is mitigated in the newer distribution (1.28r4) of linuxconf.  

An updated version (1.28r4) of linuxconf which addresses this 
vulnerability will be available on August 28, 2002 at
http://www.solucorp.qc.ca/linuxconf/ .

Affected Linux vendors will make updates available 
August 28th, 2002.


DISCLOSURE TIMELINE


August 9, 2002 - Exclusively disclosed to iDEFENSE
August 19, 2002 - Disclosed to Vendor
August 19, 2002 - Disclosed to iDEFENSE clients
August 21, 2002 - Announcement to vendor-sec@lst.de
August 28, 2002 - Coordinated public disclosure by Linux vendors,  
	Linuxconf maintainer, and iDEFENSE


CREDIT

This issue was exclusively disclosed to iDEFENSE by Euan Briggs
(euan_briggs@btinternet.com)


http://www.idefense.com/contributor.html


- -dave


David Endler, CISSP
Director, Technical Intelligence
iDEFENSE, Inc.
14151 Newbrook Drive
Suite 100
Chantilly, VA 20151
voice: 703-344-2632
fax: 703-961-1071

dendler@idefense.com
www.idefense.com


----- End forwarded message -----

-- 
 - mdz

---------------------------------------
Received: (at 158637-done) by bugs.debian.org; 11 May 2003 10:41:38 +0000
>From tbm@cyrius.com Sun May 11 05:41:37 2003
Return-path: <tbm@cyrius.com>
Received: from bangpath.uucico.de [195.71.9.197] 
	by master.debian.org with esmtp (Exim 3.12 1 (Debian))
	id 19EoGg-0005NL-00; Sun, 11 May 2003 05:41:23 -0500
Received: by bangpath.uucico.de (Postfix, from userid 10)
	id C121326BB7; Sun, 11 May 2003 12:41:21 +0200 (CEST)
Received: by regression.cyrius.com (Postfix, from userid 1000)
	id 3E2E523D48; Sun, 11 May 2003 20:40:43 +1000 (EST)
Date: Sun, 11 May 2003 20:40:43 +1000
From: Martin Michlmayr <tbm@cyrius.com>
To: 11125-done@bugs.debian.org, 58084-done@bugs.debian.org,
	101458-done@bugs.debian.org, 110796-done@bugs.debian.org,
	112769-done@bugs.debian.org, 123785-done@bugs.debian.org,
	142566-done@bugs.debian.org, 152831-done@bugs.debian.org,
	158637-done@bugs.debian.org, 160172-done@bugs.debian.org,
	161867-done@bugs.debian.org, 170483-done@bugs.debian.org,
	188936-done@bugs.debian.org
Subject: Removed
Message-ID: <20030511104043.GA28702@regression.cyrius.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4i
Delivered-To: 158637-done@bugs.debian.org
X-Spam-Status: No, hits=-7.3 required=4.0
	tests=BAYES_10,USER_AGENT_MUTT
	version=2.53-bugs.debian.org_2003_05_09
X-Spam-Level: 
X-Spam-Checker-Version: SpamAssassin 2.53-bugs.debian.org_2003_05_09 (1.174.2.15-2003-03-30-exp)

This package has been removed from Debian unstable because it has been
orphaned for a very long time and nobody adopted it.  See
http://lists.debian.org/debian-devel-announce/2003/debian-devel-announce-200304/msg00005.html
for more information.

-- 
Martin Michlmayr
tbm@cyrius.com



Reply to: