The (1) to_char and (2) to_date function in IBM DB2 8.1 allows local users to cause a denial of service (application crash) via an empty string in the second parameter, which causes a null pointer dereference.
https://exchange.xforce.ibmcloud.com/vulnerabilities/17614
http://www.securityfocus.com/bid/11400
http://www.nextgenss.com/advisories/db205012005G.txt
http://www-1.ibm.com/support/docview.wss?uid=swg1IY61781