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Gentoo Linux Security Advisory                           GLSA 201110-19
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                                            https://security.gentoo.org/
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 Severity: Normal
    Title: X.Org X Server: Multiple vulnerabilities
     Date: October 22, 2011
     Bugs: #387069
       ID: 201110-19

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Synopsis
=======
Multiple vulnerabilities in the X.Org X server might allow local
attackers to disclose information.

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       < 1.10.4-r1              *>= 1.9.5-r1 
                                                         >= 1.10.4-r1 

Description
==========
vladz reported the following vulnerabilities in the X.Org X server:

* The X.Org X server follows symbolic links when trying to access the
  lock file for a X display, showing a predictable behavior depending
  on the file type of the link target (CVE-2011-4028).
* The X.Org X server lock file mechanism allows for a race condition to
  cause the X server to modify the file permissions of an arbitrary
  file to 0444 (CVE-2011-4029).

Impact
=====
A local attacker could exploit these vulnerabilities to disclose
information by making arbitrary files on a system world-readable or
gain information whether a specified file exists on the system and
whether it is a file, directory, or a named pipe.

Workaround
=========
There is no known workaround at this time.

Resolution
=========
All X.Org X Server 1.9 users should upgrade to the latest 1.9 version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.9.5-r1"

All X.Org X Server 1.10 users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.10.4-r1"

References
=========
[ 1 ] CVE-2011-4028
      http://nvd.nist.gov/nvd.cfm?cvename=CVE-2011-4028
[ 2 ] CVE-2011-4029
      http://nvd.nist.gov/nvd.cfm?cvename=CVE-2011-4029

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

 https://security.gentoo.org/glsa/201110-19

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 2011 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/