The XML DB (XMLDB) component in Oracle Database 9.2.0.8, 9.2.0.8DV, and 10.1.0.5 generates incorrect audit entries in the USERID column in which (1) long usernames are trimmed to 5 characters, or (2) short entries contain any extra characters from usernames in previous entries, aka DB23.
http://www.vupen.com/english/advisories/2007/3626
http://www.vupen.com/english/advisories/2007/3524
http://www.us-cert.gov/cas/techalerts/TA07-290A.html
http://www.securitytracker.com/id?1018823
http://www.securityfocus.com/bid/26107
http://www.securityfocus.com/archive/1/482426/100/0/threaded
http://www.oracle.com/technetwork/topics/security/cpuoct2007-092913.html
http://www.ngssoftware.com/advisories/high-risk-vulnerability-in-oracle-xmldb-ftp-service/
http://securityreason.com/securityalert/3247
http://secunia.com/advisories/27409