This indicates an attack attempt against a buffer-overflow vulnerability in Sun Java Runtime Environment software.
The vulnerability is caused by an error when the vulnerable software handles a specially crafted Java Archive (JAR) file. It allows a remote attacker to execute arbitrary code.
Sun JDK and JRE 6 Update 10 and prior
Sun JDK and JRE 5.0 Update 16 and prior
Sun SDK and JRE 1.4.2_18 and prior
Sun SDK and JRE 1.3.1_23 and prior
Apply the patch available at the following web site: