fetchmail-SA-2006-03: crash when refusing message delivered through MDA

Topics:		fetchmail crashes when refusing a message to an MDA

Author:		Matthias Andree
Version:	1.0
Announced:	2006-11-XX
Type:		denial of service
Impact:		fetchmail aborts prematurely
Danger:		low
Credits:	Neil Hoggart (bug report and analysis)
CVE Name:	CVE-2006-XXXX
URL:		http://fetchmail.berlios.de/fetchmail-SA-2006-03.txt
Project URL:	http://fetchmail.berlios.de/

Affects:	fetchmail release = 6.3.5
		fetchmail release candidates 6.3.6-rc1, -rc2

Not affected:	fetchmail release 6.3.6

Corrected:	2006-11-14 fetchmail SVN


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

2006-11-19	internal review draft


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
=================================

Fetchmail 6.3.5 and early 6.3.6 release candidates, when delivering
messages to a message delivery agent by means of the "mda" option, can
crash (by passing a NULL pointer to ferror() and fflush()) when refusing
a message. SMTP and LMTP delivery modes aren't affected.


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

Avoid the mda option and ship to a local SMTP or LMTP server instead.


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

Download and install fetchmail 6.3.6 or a newer stable release from
fetchmail's project site at
<http://developer.berlios.de/project/showfiles.php?group_id=1824>.



A. Copyright, License and Warranty
==================================

(C) Copyright 2006 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-2006-03.txt