fetchmail-SA-2005-02: security announcement

Topic:    password exposure in fetchmailconf

Author:    Matthias Andree
Version:  1.02
Announced:  2005-10-21
Type:    insecure creation of file
Impact:    passwords are written to a world-readable file
Danger:    medium
Credits:  Thomas Wolff, Miloslav Trmac for pointing out
    that fetchmailconf 1.43.1 was also flawed
CVE Name:  CVE-2005-3088
URL:    http://fetchmail.berlios.de/fetchmail-SA-2005-02.txt

Affects:  fetchmail version 6.2.5.2
    fetchmail version 6.2.5
    fetchmail version 6.2.0
    fetchmailconf 1.43   (shipped with 6.2.0, 6.2.5 and 6.2.5.2)
    fetchmailconf 1.43.1 (shipped separately, now withdrawn)
    (other versions have not been checked but are presumed affected)

Not affected:  fetchmail 6.2.9-rc6
    fetchmailconf 1.43.2 (use this for fetchmail-6.2.5.2)
    fetchmailconf 1.49   (shipped with 6.2.9-rc6)
    fetchmail 6.3.0      (not released yet)

Corrected:  2005-09-28 01:14 UTC (SVN) - committed bugfix (r4351)
    2005-10-21                 - released fetchmailconf-1.43.2
    2005-10-21                 - released fetchmail 6.2.9-rc6

0. Release history
==================

2005-10-21  1.00 - initial version (shipped with -rc6)
2005-10-21  1.01 - marked 1.43.1 vulnerable
         - revised section 4
         - added Credits
2005-10-27  1.02 - reformatted section 0
         - updated CVE Name to new naming scheme

1. Background
=============

fetchmail is a software package to retrieve mail from remote POP2, POP3,
IMAP, ETRN or ODMR servers and forward it to local SMTP, LMTP servers or
message delivery agents.

fetchmail ships with a graphical, Python/Tkinter based configuration
utility named "fetchmailconf" to help the user create configuration (run
control) files for fetchmail.

2. Problem description and Impact
=================================

The fetchmailconf program before and excluding version 1.49 opened the
run control file, wrote the configuration to it, and only then changed
the mode to 0600 (rw-------). Writing the file, which usually contains
passwords, before making it unreadable to other users, can expose
sensitive password information.

3. Workaround
=============

Run "umask 077", then run "fetchmailconf" from the same shell. After
fetchmailconf has finished, you can restore your old umask.

4. Solution
===========

For users of fetchmail-6.2.5.2:
-------------------------------
Download fetchmailconf-1.43.2.gz from fetchmail's project site
<http://developer.berlios.de/project/showfiles.php?group_id=1824&release_id=6617>,
gunzip it, then replace your existing fetchmailconf with it.

For users of fetchmail-6.2.6* or 6.2.9* before 6.2.9-rc6:
---------------------------------------------------------
update to the latest fetchmail-devel package, 6.2.9-rc6 on 2005-10-21.
<https://developer.berlios.de/project/showfiles.php?group_id=1824>

A. References
=============

fetchmail home page: <http://fetchmail.berlios.de/>

B. Copyright, License and Warranty
==================================

(C) Copyright 2005 by Matthias Andree, <matthias.andree@gmx.de>.
Some rights reserved.

This work is licensed under the Creative Commons
Attribution-NonCommercial-NoDerivs German License. To view a copy of
this license, visit http://creativecommons.org/licenses/by-nc-nd/2.0/de/
or send a letter to Creative Commons; 559 Nathan Abbott Way;
Stanford, California 94305; USA.

THIS WORK IS PROVIDED FREE OF CHARGE AND WITHOUT ANY WARRANTIES.
Use the information herein at your own risk.

END OF fetchmail-SA-2005-02.txt