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Gentoo Linux Security Advisory                           GLSA 202104-02
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                                            https://security.gentoo.org/
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  Severity: High
     Title: X.Org X Server: Privilege escalation
      Date: April 30, 2021
      Bugs: #782679
        ID: 202104-02

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Synopsis
========

A vulnerability in X.Org X Server may allow users to escalate
privileges.

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        < 1.20.11                 >= 1.20.11

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

It was discovered that X.Org X Server did not sufficiently check the
length of the XInput extension's ChangeFeedbackControl request.

Impact
======

An authorized attacker could possibly escalate privileges, or cause a
Denial of Service condition.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

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

   # emerge --sync
   # emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.20.11"

References
==========

[ 1 ] CVE-2021-3472
       https://nvd.nist.gov/vuln/detail/CVE-2021-3472

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

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

  https://security.gentoo.org/glsa/202104-02

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 2021 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