NGSSoftware Insight Security Research Advisory

Name: IBM DB2 XML functions file creation vulnerabilities
Systems Affected: DB2 8.1
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: #NISR05012005I
Advisory URL: http://www.ngssoftware.com/advisories/db205012005I.txt

Description
***********
IBM's DB2 database server contain four XML functions that can be used to
read and write files on the system.

Details
*******
The XMLFileFromVarchar and XMLFileFromClob functions can be used to create
files on the remote server. If the file exists the original is overwritten
with the new content. The permissions of the account running DB2 is used and
not that of the user. This vulnerability can be used to create executable
binaries on the remote server as well. An attacker could create a library
for example and then load it via "CALL".

The XMLVarcharFromFile and XMLClobFromFile can be used to read files from
the remote server.

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

enquiries@ngssoftware.com