The TNS Listener, as used in Oracle Database 11g 11.1.0.7, 11.2.0.2, and 11.2.0.3, and 10g 10.2.0.3, 10.2.0.4, and 10.2.0.5, as used in Oracle Fusion Middleware, Enterprise Manager, E-Business Suite, and possibly other products, allows remote attackers to execute arbitrary database commands by performing a remote registration of a database (1) instance or (2) service name that already exists, then conducting a man-in-the-middle (MITM) attack to hijack database connections, aka "TNS Poison."
https://exchange.xforce.ibmcloud.com/vulnerabilities/75303
https://blogs.oracle.com/security/entry/security_alert_for_cve_2012
http://www.securitytracker.com/id?1027000
http://www.oracle.com/technetwork/topics/security/alert-cve-2012-1675-1608180.html
http://www.mandriva.com/security/advisories?name=MDVSA-2013:150
http://www.kb.cert.org/vuls/id/359816
http://seclists.org/fulldisclosure/2012/Apr/343
http://lists.opensuse.org/opensuse-security-announce/2012-06/msg00018.html