This indicates an attack attempt to exploit an Insecure Deserialization Vulnerability in Oracle WebLogic Server.
The vulnerability is due to an error in the vulnerable application when handling a maliciously crafted request. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted request.
Oracle WebLogic Server 10.3.6.0
Oracle WebLogic Server 188.8.131.52
Oracle WebLogic Server 184.108.40.206
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor: