The Core RDBMS component in Oracle Database 9.0.1.5+, 9.2.0.8, 9.2.0.8DV, 10.1.0.5, and 10.2.0.3 allows remote attackers to cause a denial of service (CPU consumption) via a crafted type 6 Data packet, aka DB20.
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/26108
http://www.securityfocus.com/archive/1/482424/100/0/threaded
http://www.oracle.com/technetwork/topics/security/cpuoct2007-092913.html
http://securityreason.com/securityalert/3244
http://secunia.com/advisories/27409