Gentoo: mirrorselect Insecure temporary file creation
Posted by Joe Shakespeare   
Gentoo mirrorselect is vulnerable to symlink attacks, potentially allowing a local user to overwrite arbitrary files.

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Gentoo Linux Security Advisory                        GLSA 200412-05:02
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: mirrorselect: Insecure temporary file creation
      Date: December 07, 2004
   Updated: December 07, 2004
      Bugs: #73545
        ID: 200412-05:02

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Synopsis
========

mirrorselect is vulnerable to symlink attacks, potentially allowing a
local user to overwrite arbitrary files.

Background
==========

mirrorselect is a tool to help select distfiles mirrors for Gentoo.

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

    -------------------------------------------------------------------
     Package                   /  Vulnerable  /             Unaffected
    -------------------------------------------------------------------
  1  app-portage/mirrorselect       < 0.89                     >= 0.89

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

Ervin Nemeth discovered that mirrorselect creates temporary files in
world-writable directories with predictable names.

Impact
======

A local attacker could create symbolic links in the temporary files
directory, pointing to a valid file somewhere on the filesystem. When
mirrorselect is executed, this would result in the file being
overwritten with the rights of the user running the utility, which
could be the root user.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All mirrorselect users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=app-portage/mirrorselect-0.89"

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

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

  http://security.gentoo.org/glsa/glsa-200412-05.xml

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
http://bugs.gentoo.org.

License
=======

Copyright 2004 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/2.0