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

[Thierry Carrez <koon () gentoo org>]

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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          < 0.37.4                        >= 0.37.4
  2  app-doc/kchmviewer        < 1.1                            >= 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 ">=app-doc/chmlib-0.37.4"

All KchmViewer users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=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

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