[ GLSA 200909-01 ] Linux-PAM: Privilege escalation

[Alex Legler <a3li () gentoo org>]

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Gentoo Linux Security Advisory                           GLSA 200909-01
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                                            http://security.gentoo.org/
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  Severity: Normal
     Title: Linux-PAM: Privilege escalation
      Date: September 07, 2009
      Bugs: #261512
        ID: 200909-01

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Synopsis
========

An error in the handling of user names of Linux-PAM might allow remote
attackers to cause a Denial of Service or escalate privileges.

Background
==========

Linux-PAM (Pluggable Authentication Modules) is an architecture
allowing the separation of the development of privilege granting
software from the development of secure and appropriate authentication
schemes.

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

    -------------------------------------------------------------------
     Package       /  Vulnerable  /                         Unaffected
    -------------------------------------------------------------------
  1  sys-libs/pam       < 1.0.4                               >= 1.0.4

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

Marcus Granado repoted that Linux-PAM does not properly handle user
names that contain Unicode characters. This is related to integer
signedness errors in the pam_StrTok() function in libpam/pam_misc.c.

Impact
======

A remote attacker could exploit this vulnerability to cause a Denial of
Service. A remote authenticated attacker could exploit this
vulnerability to log in to a system with the account of a user that has
a similar user name, but with non-ASCII characters.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All Linux-PAM users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose =sys-libs/pam-1.0.4

References
==========

  [ 1 ] CVE-2009-0887
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-0887

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

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

  http://security.gentoo.org/glsa/glsa-200909-01.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
https://bugs.gentoo.org.

License
=======

Copyright 2009 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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