NGSSoftware Insight Security Research Advisory

Name: IBM DB2 libdb2.so.1 buffer overflow
Systems Affected: DB2 8.1/7.x  
Severity: High risk from local
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: #NISR05012005B
Advisory URL: http://www.ngssoftware.com/advisories/db205012005B.txt

Description
***********
libdb2.so.1, one of the libraries supplied with IBM's DB2 database server
suffers from a buffer overflow vulnerability.

Details
*******
This vulnerability can be divided into two separate issues. Firstly, when
libdb2.so is loaded it reads the DBLPORT environment variable and copies the
value to a buffer in the .bss section. This buffer is overflowed. By
providing an overly long DB2LPORT environment variable it fills the
db2MLNPort_name buffer in the .bss section of libdb2.so.1 - then spills over
into the db2node_name buffer, into the instprof_path buffer, into the
instance_path buffer and so on all the way into the install_path buffer.
Secondly, when the sqloInstancePath() reads the install_path we overflow a
local stack based buffer of sqloGetInstancePath().

This can be exploited to gain root privileges. For example, db2cacpy is
setuid root. This program loads the library and calls sqloInstancePath()
overflowing the buffer.



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/

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