GLSA 200405-07: Exim verify=header_syntax buffer overflow
Posted on: 05/15/2004 04:52 AM

An Exim securty update has been released for Gentoo Linux

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Gentoo Linux Security Advisory GLSA 200405-07
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http://security.gentoo.org/
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Severity: High
Title: Exim verify=header_syntax buffer overflow
Date: May 14, 2004
Bugs: #50217
ID: 200405-07

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Synopsis
=======

When the verify=header_syntax option is set, there is a buffer overflow in Exim that allows remote execution of arbitrary code.

Background
=========

Exim is an highly configurable message transfer agent (MTA) developed at the University of Cambridge.

Affected packages
================

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Package / Vulnerable / Unaffected
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1 net-mail/exim <= 4.33 >= 4.33-r1

Description
==========

When the option "verify = header_syntax" is used in an ACL in the configuration file, Exim is vulnerable to a buffer overflow attack that can be triggered remotely by sending malicious headers in an email message. Note that this option is not enabled in Exim's default configuration file.

Impact
=====

This vulnerability can be exploited to trigger a denial of service attack and potentially execute arbitrary code with the rights of the user used by the Exim daemon (by default this is the "mail" user in Gentoo Linux).

Workaround
=========

Make sure the verify=header_syntax option is not used in your exim.conf file.

Resolution
=========

All users of Exim should upgrade to the latest stable version:

# emerge sync

# emerge -pv ">=net-mail/exim-4.33-r1"
# emerge ">=net-mail/exim-4.33-r1"

References
=========

[ 1 ] CAN-2004-0400
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0400

Availability
===========

This GLSA and any updates to it are available for viewing at the Gentoo Security Website:

http://security.gentoo.org/glsa/glsa-200405-07.xml

Concerns?
========

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at http://bugs.gentoo.org.

License
======

Copyright 2004 Gentoo Technologies, Inc; referenced text belongs to its owner(s).

The contents of this document are licensed under the Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/1.0


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