A new security update has been released for Gentoo Linux - X.Org X server and Xfont library: Multiple vulnerabilities. Here the announcement:

Gentoo Linux Security Advisory GLSA 200801-09
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http://security.gentoo.org/
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Severity: High
Title: X.Org X server and Xfont library: Multiple vulnerabilities
Date: January 20, 2008
Bugs: #204362
ID: 200801-09

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Synopsis
========

Multiple vulnerabilities have been discovered in the X.Org X server and
Xfont library, allowing for a local privilege escalation and arbitrary
code execution.

Background
==========

The X Window System is a graphical windowing system based on a
client/server model.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 x11-base/xorg-server < 1.3.0.0-r4 >= 1.3.0.0-r4
2 x11-libs/libxfont < 1.3.1-r1 >= 1.3.1-r1
-------------------------------------------------------------------
2 affected packages on all of their supported architectures.
-------------------------------------------------------------------

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

regenrecht reported multiple vulnerabilities in various X server
extension via iDefense:

* The XFree86-Misc extension does not properly sanitize a parameter
within a PassMessage request, allowing the modification of a function
pointer (CVE-2007-5760).

* Multiple functions in the XInput extension do not properly sanitize
client requests for swapping bytes, leading to corruption of heap
memory (CVE-2007-6427).

* Integer overflow vulnerabilities in the EVI extension and in the
MIT-SHM extension can lead to buffer overflows (CVE-2007-6429).

* The TOG-CUP extension does not sanitize an index value in the
ProcGetReservedColormapEntries() function, leading to arbitrary
memory access (CVE-2007-6428).

* A buffer overflow was discovered in the Xfont library when
processing PCF font files (CVE-2008-0006).

* The X server does not enforce restrictions when a user specifies a
security policy file and attempts to open it (CVE-2007-5958).

Impact
======

Remote attackers could exploit the vulnerability in the Xfont library
by enticing a user to load a specially crafted PCF font file resulting
in the execution of arbitrary code with the privileges of the user
running the X server, typically root. Local attackers could exploit
this and the vulnerabilities in the X.org extensions to gain elevated
privileges. If the X server allows connections from the network, these
vulnerabilities could be exploited remotely. A local attacker could
determine the existence of arbitrary files by exploiting the last
vulnerability or possibly cause a Denial of Service.

Workaround
==========

Workarounds for some of the vulnerabilities can be found in the X.Org
security advisory as listed under References.

Resolution
==========

All X.Org X server users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.3.0.0-r4"

All X.Org Xfont library users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-libs/libXfont-1.3.1-r1"

References
==========

[ 1 ] CVE-2007-5760
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5760
[ 2 ] CVE-2007-5958
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5958
[ 3 ] CVE-2007-6427
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6427
[ 4 ] CVE-2007-6428
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6428
[ 5 ] CVE-2007-6429
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6429
[ 6 ] CVE-2008-0006
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0006
[ 7 ] X.Org security advisory
http://lists.freedesktop.org/archives/xorg/2008-January/031918.html

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

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

http://security.gentoo.org/glsa/glsa-200801-09.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 2008 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