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Gentoo Linux Security Advisory                           GLSA 201705-15
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                                           https://security.gentoo.org/
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 Severity: High
    Title: sudo: Privilege escalation
     Date: May 30, 2017
     Bugs: #620182
       ID: 201705-15

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Synopsis
========

A vulnerability in sudo allows local users to gain root privileges.

Background
==========

sudo (su "do") allows a system administrator to delegate authority to
give certain users (or groups of users) the ability to run some (or
all) commands as root or another user while providing an audit trail of
the commands and their arguments.

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

    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  app-admin/sudo             < 1.8.20_p1              >= 1.8.20_p1

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

Qualys discovered a vulnerability in sudo's get_process_ttyname() for
Linux, that via sudo_ttyname_scan() can be directed to use a
user-controlled, arbitrary tty device during its traversal of "/dev" by
utilizing the world-writable /dev/shm.

Impact
======

A local attacker can pretend that his tty is any character device on
the filesystem, and after two race conditions, an attacker can pretend
that the controlled tty is any file on the filesystem allowing for
privilege escalation

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All sudo users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=app-admin/sudo-1.8.20_p1"

References
==========

[ 1 ] CVE-2017-1000367
      http://nvd.nist.gov/nvd.cfm?cvename=CVE-2017-1000367

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

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

 https://security.gentoo.org/glsa/201705-15

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 2017 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