[ GLSA 200609-07 ] LibXfont, monolithic X.org: Multiple integer overflows

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Gentoo Linux Security Advisory GLSA 200609-07
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                                            http://security.gentoo.org/
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  Severity: High
     Title: LibXfont, monolithic X.org: Multiple integer overflows
      Date: September 13, 2006
      Bugs: #145513
        ID: 200609-07

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Synopsis
========

Some buffer overflows were discovered in the CID font parser,
potentially resulting in the execution of arbitrary code with elevated
privileges.

Background
==========

libXfont is the X.Org Xfont library, some parts are based on the
FreeType code base.

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

    -------------------------------------------------------------------
     Package / Vulnerable / Unaffected
    -------------------------------------------------------------------
  1 x11-libs/libXfont < 1.2.1 >= 1.2.1
  2 x11-base/xorg-x11 < 7.0 >= 7.0
    -------------------------------------------------------------------
     2 affected packages on all of their supported architectures.
    -------------------------------------------------------------------

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

Several integer overflows have been found in the CID font parser.

Impact
======

A remote attacker could exploit this vulnerability by enticing a user
to load a malicious font file resulting in the execution of arbitrary
code with the permissions of the user running the X server which
typically is the root user. A local user could exploit this
vulnerability to gain elevated privileges.

Workaround
==========

Disable CID-encoded Type 1 fonts by removing the "type1" module and
replacing it with the "freetype" module in xorg.conf.

Resolution
==========

All libXfont users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=x11-libs/libXfont-1.2.1"

All monolithic X.org users are advised to migrate to modular X.org.

References
==========

  [ 1 ] CVE-2006-3739
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=2006-3739
  [ 2 ] CVE-2006-3740
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=2006-3740

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

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

  http://security.gentoo.org/glsa/glsa-200609-07.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_at_gentoo.org or alternatively, you may file a bug at
http://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.

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

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