NGSSoftware Insight Security Research Advisory

Name: IBM DB2 call buffer overflow
Systems Affected: DB2 8.1/7.x  
Severity: High risk from remote
Vendor URL: http://www.ibm.com/
Author: David Litchfield [ david at ngssoftware.com ]
Relates to: http://www.nextgenss.com/advisories/db2-02.txt
Date of Public Advisory: 5th January 2005
Advisory number: #NISR05012005C
Advisory URL: http://www.ngssoftware.com/advisories/db205012005C.txt

Description
***********
IBM's DB2 database server suffers from a stack based buffer overflow
vulnerability when using "call".

Details
*******
Under DB2 it is possible to load a library directly and execute a function:

call libname!function

By passing an overly long libname it is possible to overflow a stack based
buffer and overwrite the saved return address. When exploited this can allow
an attacker to gain elevated privileges.


Note 1) if an attacker can place an arbitrary library on the system (and
there are ways to do this via DB2 and SQL) then there is no need to exploit
this overflow. It is sufficient simply to create the library and export a
function that takes no parameters.

Note 2) "CREATE WRAPPERS" uses the same code as "CALL" and is presents
another vector.


Fix Information
***************
IBM has written a patch and can be obtained with the latest fixpak.

http://www-306.ibm.com/software/data/db2/udb/support/downloadv8.html - DB2
v8.1
http://www-306.ibm.com/software/data/db2/udb/support/downloadv7.html - DB2
v7.x

NGSSQuirreL for DB2 (http://www.nextgenss.com/db2.htm) can be used to assess
whether your DB2 server is vulnerable to this.


About NGSSoftware
*****************
NGSSoftware design, research and develop intelligent, advanced application
security assessment scanners. Based in the United Kingdom, NGSSoftware have
offices in the South of London and the East Coast of Scotland. NGSSoftware's
sister company NGSConsulting, offers best of breed security consulting
services, specialising in application, host and network security
assessments.

http://www.ngssoftware.com/

Telephone +44 208 401 0070
Fax +44 208 401 0076

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