chmlib, KchmViewer: Stack-based buffer overflow

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200511-23 / chmlib kchmviewer
Release Date	November 28, 2005
Latest Revision	May 28, 2009: 03
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
dev-libs/chmlib	< 0.37.4	>= 0.37.4	All supported architectures
app-text/kchmviewer	< 1.1	>= 1.1	All supported architectures

Related bugreports: #110557

Synopsis

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

2. Impact Information

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.

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.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All chmlib users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/chmlib-0.37.4"

All KchmViewer users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=app-text/kchmviewer-1.1"

4. References

CVE-2005-3318

Updated November 28, 2005

Summary: This is a Gentoo Linux Security Advisory

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