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Gentoo Linux Security Advisory                           GLSA 202210-26
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                                           https://security.gentoo.org/
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 Severity: Normal
    Title: Shadow: TOCTOU Race
     Date: October 31, 2022
     Bugs: #830486
       ID: 202210-26

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Synopsis
=======
A TOCTOU race has been discovered in Shadow, which could result in the
unauthorized modification of files.

Background
=========
Shadow contains utilities to deal with user accounts

Affected packages
================
    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  sys-apps/shadow            < 4.12.2                    >= 4.12.2

Description
==========
A TOCTOU race condition was discovered in shadow. A local attacker with
write privileges in a directory removed or copied by usermod/userdel
could potentially exploit this flaw when the administrator invokes
usermod/userdel.

Impact
=====
An unauthorized user could potentially modify files which they do not
have write permissions for.

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

Resolution
=========
All Shadow users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=sys-apps/shadow-4.12.2"

References
=========
[ 1 ] CVE-2013-4235
      https://nvd.nist.gov/vuln/detail/CVE-2013-4235

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

 https://security.gentoo.org/glsa/202210-26

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 2022 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/