n.runs AG                      
http://www.nruns.com/ security(at)nruns.com 
n.runs-SA-2007.025                                           24-Aug-2007

________________________________________________________________________ 

Vendor: ClamAV, http://www.clamav.net 
Affected Products:      ClamAV, 
http://www.clamav.net 
Vulnerability :         Remote Code Execution
Risk:                   HIGH 

________________________________________________________________________ 

Vendor communication: 


  2007/08/10 Initial notification to ClamAV 
  2007/08/10 ClamAV Responses 
  2007/08/10 PoC files sent to ClamAV 
  2007/08/21 ClamAV releases version 0.91.2
  2007/08/24 n.runs AG releases a coordinated disclosure advisory 
________________________________________________________________________ 

Overview:

Clam AntiVirus is an open source (GPL) anti-virus toolkit for UNIX,
designed especially for e-mail scanning on mail gateways. It provides
a number of utilities including a flexible and scalable multi-threaded
daemon, a command line scanner and advanced tool for automatic database
updates. The core of the package is an anti-virus engine available in
a form of shared library.

Description:

A remotely exploitable vulnerability has been found in clamav-milter
when used with sendmail. In detail, the following flaw was determined:

- Arbitrary code execution due to insecure call to popen()

Impact:

This vulnerability can lead to remote code execution with root privileges.
Leading to a complete compromise of the vulnerable system.
An attacker can inject shell commands into the recipient field of sendmail,
if clamav-milter was started with the black hole mode activated.
The vulnerability is present in at least clamav version 0.91.1, prior
versions may also be affected.

Solution:
A new stable release (clamav 0.91.2) is available at the clamav website
which
fixes the vulnerability.

________________________________________________________________________ 


Credit:
Bugs found by Nikolaos Rangos of n.runs AG. 
________________________________________________________________________ 


References:
http://www.clamav.net/download/sources 


This Advisory and Upcoming Advisories 
http://www.nruns.com/security_advisory.php 
http://www.nruns.com/parsing-engines-advisories.php 
________________________________________________________________________ 


Unaltered electronic reproduction of this advisory is permitted. For all 
other reproduction or publication, in printing or otherwise, contact 
securitynruns.com for permission. Use of the advisory constitutes 
acceptance for use in an as is condition. All warranties are excluded. In 
no event shall n.runs be liable for any damages whatsoever including direct,

indirect, incidental, consequential, loss of business profits or special 
damages, even if n.runs has been advised of the possibility of such damages.




Copyright 2007 n.runs AG. All rights reserved. Terms of use apply.