This indicates an attack attempt against a Sandbox Bypass Vulnerability in Oracle Java Runtime Environment.
The vulnerability is due to improper checks and handling of certain Java methods. An attacker can exploit this by tricking an unsuspecting user into visiting a webpage containing a malicious Java applet and execute Java code within the security context of the user.
Oracle JDK and JRE 7 Update 6 and earlier versions
Oracle JDK and JRE 6 Update 34 and earlier versions
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patch available from the website.