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Gentoo Linux Security Advisory                           GLSA 202011-07
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                                           https://security.gentoo.org/
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 Severity: Normal
    Title: Mozilla Firefox: Remote code execution
     Date: November 11, 2020
     Bugs: #753773
       ID: 202011-07

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Synopsis
========

A use-after-free in Mozilla Firefox might allow remote attacker(s) to
execute arbitrary code.

Background
==========

Mozilla Firefox is a popular open-source web browser from the Mozilla
project.

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

    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  www-client/firefox           < 82.0.3          >= 78.4.1:0/esr78
                                                            >= 82.0.3
  2  www-client/firefox-bin       < 78.4.1          >= 78.4.1:0/esr78
                                                            >= 82.0.3
    -------------------------------------------------------------------
     2 affected packages

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

Invalid assumptions when emitting the the MCallGetProperty opcode in
the JavaScript JIT may result in a use-after-free condition.

Impact
======

A remote attacker could possibly execute arbitrary code with the
privileges of the process, or cause a Denial of Service condition.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Mozilla Firefox users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=www-client/firefox-82.0.3"

All Mozilla Firefox (bin) users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot -v ">=www-client/firefox-bin-78.4.1:0/esr78"

All Mozilla Firefox (ESR) users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=www-client/firefox-82.0.3"

All Mozilla Firefox (ESR) bin users should upgrade to the latest
version:

  # emerge --sync
  # emerge --ask --oneshot -v ">=www-client/firefox-bin-78.4.1:0/esr78"

References
==========

[ 1 ] CVE-2020-26950
      https://nvd.nist.gov/vuln/detail/CVE-2020-26950
[ 2 ] MFSA-2020-49
      https://www.mozilla.org/en-US/security/advisories/mfsa2020-49/

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

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

 https://security.gentoo.org/glsa/202011-07

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
[email protected] or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2020 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