GLSA 200710-11 X Font Server: Multiple Vulnerabilities

Gentoo Linux Security Advisory GLSA 200710-11
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http://security.gentoo.org/
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Severity: High
Title: X Font Server: Multiple Vulnerabilities
Date: October 12, 2007
Bugs: #185660, #194606
ID: 200710-11

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Synopsis
========

Three vulnerabilities have been discovered in the X Font Server
possibly allowing local attackers to gain elevated privileges.

Background
==========

The X.Org X11 X Font Server provides a standard mechanism for an X
server to communicate with a font renderer.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 x11-apps/xfs lt; 1.0.5 gt;= 1.0.5

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

iDefense reported that the xfs init script does not correctly handle a
race condition when setting permissions of a temporary file
(CVE-2007-3103). Sean Larsson discovered an integer overflow
vulnerability in the build_range() function possibly leading to a
heap-based buffer overflow when handling "QueryXBitmaps" and
"QueryXExtents" protocol requests (CVE-2007-4568). Sean Larsson also
discovered an error in the swap_char2b() function possibly leading to a
heap corruption when handling the same protocol requests
(CVE-2007-4990).

Impact
======

The first issue would allow a local attacker to change permissions of
arbitrary files to be world-writable by performing a symlink attack.
The second and third issues would allow a local attacker to execute
arbitrary code with privileges of the user running the X Font Server,
usually xfs.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All X Font Server users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=x11-apps/xfs-1.0.5"

References
==========

[ 1 ] CVE-2007-3103
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-3103
[ 2 ] CVE-2007-4568
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4568
[ 3 ] CVE-2007-4990
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4990

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

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

http://security.gentoo.org/glsa/glsa-200710-11.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