NGSSoftware Insight Security Research Advisory Name: IBM DB2 JDBC Applet Server buffer overflow 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: #NISR05012005D Advisory URL: http://www.ngssoftware.com/advisories/db205012005D.txt Description *********** IBM's DB2 JDBC Applet Server suffers from a stack based buffer overflow vulnerability that can be exploited remotely without a user ID or password. Details ******* When a client connects to the JDBC applet server on TCP port 6789 it does so using a proprietary protocol. The connection packet starts with ValidDb2jdTokenFromTheClientSide and includes the username, the password, the db2java.zip version and the database to connect to. The problem arises as follows. Firstly, an attacker attempts to authenticate to the JDBC applet server on TCP 6789 with an overly long username of c. 2200 bytes then disconnects gracefully. Secondly, they reconnect, but this time send a short username but set the db2java.zip version to something other than expected by the server. Set the version to c. 544 unicode bytes \x00\x41. An error is logged and at some stage the null terminator is removed and the original username that was sent is concatentated to the db2java.zip version. This is then copied to a stack based buffer and it overflows. 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@xxxxxxxxxxxxxxx
