Gentoo: poppassd_pam Unauthorized password changing
Posted by Joe Shakespeare   
Gentoo poppassd_pam allows anyone to change any user's password without authenticating the user first.

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Gentoo Linux Security Advisory                           GLSA 200501-22
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                                            http://security.gentoo.org/
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  Severity: High
     Title: poppassd_pam: Unauthorized password changing
      Date: January 11, 2005
      Bugs: #75820
        ID: 200501-22

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Synopsis
========

poppassd_pam allows anyone to change any user's password without
authenticating the user first.

Background
==========

poppassd_pam is a PAM-enabled server for changing system passwords that
can be used to change POP server passwords.

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

    -------------------------------------------------------------------
     Package                 /  Vulnerable  /               Unaffected
    -------------------------------------------------------------------
     net-mail/poppassd_ceti       <= 1.0                      >= 1.8.4
     net-mail/poppassd_pam        <= 1.0                   Vulnerable!
    -------------------------------------------------------------------

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

Gentoo Linux developer Marcus Hanwell discovered that poppassd_pam did
not check that the old password was valid before changing passwords.
Our investigation revealed that poppassd_pam did not call
pam_authenticate before calling pam_chauthtok.

Impact
======

A remote attacker could change the system password of any user,
including root. This leads to a complete compromise of the POP
accounts, and may also lead to a complete root compromise of the
affected server, if it also provides shell access authenticated using
system passwords.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All poppassd_pam users should migrate to the new package called
poppassd_ceti:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-mail/poppassd_ceti-1.8.4"

Note: Portage will automatically replace the poppassd_pam package by
the poppassd_ceti package.

References
==========

  [ 1 ] CAN-2005-0002
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0002

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

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

  http://security.gentoo.org/glsa/glsa-200501-22.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 2005 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