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Gentoo Linux Security Advisory                           GLSA 200607-06
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                                            https://security.gentoo.org/
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  Severity: Normal
     Title: libpng: Buffer overflow
      Date: July 19, 2006
      Bugs: #138433, #138672
        ID: 200607-06

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Synopsis
=======
A buffer overflow has been found in the libpng library that could lead
to the execution of arbitrary code.

Background
=========
libpng is an open, extensible image format library, with lossless
compression.

Affected packages
================
    -------------------------------------------------------------------
     Package                  /  Vulnerable  /              Unaffected
    -------------------------------------------------------------------
  1  libpng                       < 1.2.12                   >= 1.2.12
  2  emul-linux-x86-baselibs       < 2.5.1                    >= 2.5.1
    -------------------------------------------------------------------
     # Package 2 [app-emulation/emul-linux-x86-baselibs] only applies
       to AMD64 users.

     NOTE: Any packages listed without architecture tags apply to all
           architectures...
    -------------------------------------------------------------------
     2 affected packages
    -------------------------------------------------------------------

Description
==========
In pngrutil.c, the function png_decompress_chunk() allocates
insufficient space for an error message, potentially overwriting stack
data, leading to a buffer overflow.

Impact
=====
By enticing a user to load a maliciously crafted PNG image, an attacker
could execute arbitrary code with the rights of the user, or crash the
application using the libpng library, such as the
emul-linux-x86-baselibs.

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-1.2.12"

All AMD64 emul-linux-x86-baselibs users should also upgrade to the
latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose
">=app-emulation/emul-linux-x86-baselibs-2.5.1"

References
=========
  [ 1 ] libpng Changelog

  [ 2 ] CVE-2006-3334
        
Availability
===========
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  https://security.gentoo.org/glsa/200607-06

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
https://bugs.gentoo.org/.

License
======
Copyright 2006 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.

https://creativecommons.org/licenses/by-sa/2.5/