GLSA 200511-23 chmlib, KchmViewer: Stack-based buffer overflow

Gentoo Linux Security Advisory GLSA 200511-23
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http://security.gentoo.org/
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Severity: Normal
Title: chmlib, KchmViewer: Stack-based buffer overflow
Date: November 28, 2005
Bugs: #110557
ID: 200511-23

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Synopsis
========

chmlib and KchmViewer contain a buffer overflow vulnerability which may
lead to the execution of arbitrary code.

Background
==========

chmlib is a library for dealing with Microsoft ITSS and CHM format
files. KchmViewer is a CHM viewer that includes its own copy of the
chmlib library.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 app-doc/chmlib lt; 0.37.4 gt;= 0.37.4
2 app-doc/kchmviewer lt; 1.1 gt;= 1.1
-------------------------------------------------------------------
2 affected packages on all of their supported architectures.
-------------------------------------------------------------------

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

Sven Tantau reported about a buffer overflow vulnerability in chmlib.
The function "_chm_decompress_block()" does not properly perform
boundary checking, resulting in a stack-based buffer overflow.

Impact
======

By convincing a user to open a specially crafted ITSS or CHM file,
using KchmViewer or a program makes use of chmlib, a remote attacker
could execute arbitrary code with the privileges of the user running
the software.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All chmlib users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=app-doc/chmlib-0.37.4"

All KchmViewer users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=app-doc/kchmviewer-1.1"

References
==========

[ 1 ] CVE-2005-3318
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-3318

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

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

http://security.gentoo.org/glsa/glsa-200511-23.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 2005 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/2.0