A new security update has been released for Gentoo Linux - libpng: Multiple Denials of Service. Here the announcement:

Gentoo Linux Security Advisory GLSA 200711-08
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http://security.gentoo.org/
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Severity: Normal
Title: libpng: Multiple Denials of Service
Date: November 07, 2007
Bugs: #195261
ID: 200711-08

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Synopsis
========

Several vulnerabilities in libpng may allow a remote attacker to crash
applications that handle untrusted images.

Background
==========

libpng is a free ANSI C library used to process and manipulate PNG
images.

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

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Package / Vulnerable / Unaffected
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1 media-libs/libpng < 1.2.21-r3 >= 1.2.21-r3

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

An off-by-one error when handling ICC profile chunks in the
png_set_iCCP() function was discovered (CVE-2007-5266). George Cook and
Jeff Phillips reported several errors in pngrtran.c, the use of logical
instead of a bitwise functions and incorrect comparisons
(CVE-2007-5268). Tavis Ormandy reported out-of-bounds read errors in
several PNG chunk handling functions (CVE-2007-5269).

Impact
======

A remote attacker could craft an image that when processed or viewed by
an application using libpng would cause the application to terminate
abnormally.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All libpng users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/libpng-1.2.21-r3"

References
==========

[ 1 ] CVE-2007-5266
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5266
[ 2 ] CVE-2007-5268
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5268
[ 3 ] CVE-2007-5269
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5269

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

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

http://security.gentoo.org/glsa/glsa-200711-08.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 2007 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/2.5