[ GLSA 200408-19 ] courier-imap: Remote Format String Vulner

[pahud]

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Gentoo Linux Security Advisory GLSA 200408-19
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http://security.gentoo.org/
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Severity: High
Title: courier-imap: Remote Format String Vulnerability
Date: August 19, 2004
Bugs: #60865
ID: 200408-19

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Synopsis
========

There is a format string vulnerability in non-standard configurations
of courier-imapd which may be exploited remotely. An attacker may be
able to execute arbitrary code as the user running courier-imapd
(oftentimes root).

Background
==========

Courier-IMAP is an IMAP server which is part of the Courier mail
system. It provides access only to maildirs.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 net-mail/courier-imap <= 3.0.2-r1 >= 3.0.5

Description
===========

There is a format string vulnerability in the auth_debug() function
which can be exploited remotely, potentially leading to arbitrary code
execution as the user running the IMAP daemon (oftentimes root). A
remote attacker may send username or password information containing
printf() format tokens (such as "%s"), which will crash the server or
cause it to execute arbitrary code.

This vulnerability can only be exploited if DEBUG_LOGIN is set to
something other than 0 in the imapd config file.

Impact
======

If DEBUG_LOGIN is enabled in the imapd configuration, a remote attacker
may execute arbitrary code as the root user.

Workaround
==========

Set the DEBUG_LOGIN option in /etc/courier-imap/imapd to 0. (This is
the default value.)

Resolution
==========

All courier-imap users should upgrade to the latest version:

# emerge sync

# emerge -pv ">=net-mail/courier-imap-3.0.5"
# emerge ">=net-mail/courier-imap-3.0.5"

References
==========

[ 1 ] iDEFENSE Advisory
http://www.idefense.com/application/poi ... tatus=true

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

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

http://security.gentoo.org/glsa/glsa-200408-19.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 Foundation, 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