[ GLSA 200612-19 ] pam_ldap: Authentication bypass vulnerability

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Gentoo Linux Security Advisory GLSA 200612-19
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                                            http://security.gentoo.org/
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  Severity: Low
     Title: pam_ldap: Authentication bypass vulnerability
      Date: December 20, 2006
      Bugs: #153916
        ID: 200612-19

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Synopsis
========

pam_ldap contains a vulnerability that may allow a remote user with a
locked account to gain unauthorized system access.

Background
==========

pam_ldap is a Pluggable Authentication Module which allows
authentication against LDAP directories.

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

    -------------------------------------------------------------------
     Package / Vulnerable / Unaffected
    -------------------------------------------------------------------
  1 sys-auth/pam_ldap < 183 >= 183

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

Steve Rigler discovered that pam_ldap does not correctly handle
"PasswordPolicyResponse" control responses from an LDAP directory. This
causes the pam_authenticate() function to always succeed, even if the
previous authentication failed.

Impact
======

A locked user may exploit this vulnerability to bypass the LDAP
authentication mechanism, possibly gaining unauthorized access to the
system.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All pam_ldap users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=sys-auth/pam_ldap-183"

References
==========

  [ 1 ] CVE-2006-5170
        http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-5170

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

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

  http://security.gentoo.org/glsa/glsa-200612-19.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_at_gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2006 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

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