[PLSA 2008-25] Postfix: Local privilege escalation

[Pınar Yanardağ <pinar () pardus org tr>]

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Pardus Linux Security Advisory 2008-25            security () pardus org tr
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       Date: 2008-08-16
   Severity: 2
       Type: Local
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Summary
=======

Sebastian Krahmer has reported some security issues in  Postfix,  which
can be exploited by malicious,  local  users  to  disclose  potentially
sensitive  information and  perform  certain  actions  with  escalated
privileges.


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

1) A security issue is  caused  due  to  Postfix  incorrectly  handling
symlink files. This can be exploited to e.g. append  mail  messages  to
arbitrary files by creating a hardlink to a symlink owned by  the  root
user.

Successful exploitation requires write permission  to  the  mail  spool
directory, that there is no "root" mailbox,  and  users  can  create  a
hardlink to a symlink.

2) A security issue is caused due to Postfix not correctly checking the
ownership  of the  destination  when  delivering  email.  This  can  be
exploited to e.g. disclose emails by creating an insecure mailbox  file
for other users.

Affected packages:

   Pardus 2008:
     postfix, all before 2.5.4-20-4
   Pardus 2007:
     postfix, all before 2.3.4-12-11


Resolution
==========

There are update(s) for postfix. You can update them via Package Manager
or with a single command from console:

   Pardus 2008:
     pisi up postfix

   Pardus 2007:
     pisi up postfix


References
==========

   * http://de.postfix.org/ftpmirror/official/postfix-2.5.4.HISTORY
   * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2936
   * http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2937
   * http://lists.opensuse.org/opensuse-security-announce/2008-08/msg00002.html
   * http://secunia.com/advisories/31485

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-- 
Pardus Security Team
http://security.pardus.org.tr


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