<<< Date Index >>>     <<< Thread Index >>>

SRT2003-11-11-1151 - clamav-milter remote exploit / DoS



Secure Network Operations, Inc.             http://www.secnetops.com/research
Strategic Reconnaissance Team               research@xxxxxxxxxxxxx
Team Lead Contact                           kf@xxxxxxxxxxxxx


Our Mission:
************************************************************************
Secure Network Operations offers expertise in Networking, Intrusion 
Detection Systems (IDS), Software Security Validation, and 
Corporate/Private Network Security. Our mission is to facilitate a 
secure and reliable Internet and inter-enterprise communications 
infrastructure through the products and services we offer. 

To learn more about our company, products and services or to request a 
demo of ANVIL FCS please visit our site at http://www.secnetops.com, or 
call us at: 978-263-3829


Quick Summary:
************************************************************************
Advisory Number         : SRT2003-11-11-1151
Product                 : Clam AntiVirus
Version                 : clamav-0.60 through clamav-0.60p
Vendor                  : http://clamav.elektrapro.com/
Class                   : Remote
Criticality             : High (to clamav-milter users)
Operating System(s)     : *nix, cygwin


Notice
************************************************************************
The full technical details of this vulnerability can be found at:
http://www.secnetops.com under the research section. 


Basic Explanation
************************************************************************
High Level Description  : clamav-milter contains format strings issues.
What to do              : disable syslog support, upgrade to clamav-0.65


Basic Technical Details
************************************************************************
Proof Of Concept Status : SNO has proof of concept. 

Low Level Description   : Clam AntiVirus is an anti-virus toolkit for 
UNIX. The main purpose of the software is to integrate with mail servers 
for attachment scanning. Clam AntiVirus works with Linux, Solaris, 
FreeBSD, OpenBSD, NetBSD, AIX, Mac OS X, and Cygwin B20.

Snapshot clamav-devel-20031111 and clamav-0.65 fix a potentially 
exploitable format string issue that can be triggered by a remote attacker. 
Only versions above clamav-0.54 that include syslog() functionality are 
vulnerable to this attack. CVS snapshots up to but not including version 
clamav-devel-20031111 may be vulnerable to attack. Versions clamav-0.60 
through clamav-0.60p are confirmed to be at least exploitable for a DoS 
condition. This issue only poses a problem for clamav-milter users.

*    0.60q   11/11/03 Fixed handling of % characters in e-mail addresses
*    pointed out by dotslash@xxxxxxxxxxx

This issue may potentially be used to run code as either the clamav user or
root depending on how clamav is configured. At the very least a DoS attack
on clamav-milter can be caused using "mail from: %n%n%n%n%n%n%n" along with 
a test antivirus string which is used to trigger an AV alert.

full details at http://www.secnetopz.biz/research/SRT2003-11-11-1151.txt

Vendor Status           : Promptly attended to the issue. Patched
clamav-milter is available in clamav-devel-20031111 and clamav-0.65

Bugtraq URL             : To be assigned. 
Disclaimer
----------------------------------------------------------------------
This advisory was released by Secure Network Operations,Inc. as a matter
of notification to help administrators protect their networks against
the described vulnerability. Exploit source code is no longer released
in our advisories but can be obtained under contract.. Contact our sales 
department at sales@xxxxxxxxxxxxx for further information on how to 
obtain proof of concept code.

----------------------------------------------------------------------
Secure Network Operations, Inc. || http://www.secnetops.com
"Embracing the future of technology, protecting you."