This indicates an attack attempt to exploit an Insecure Deserialization Vulnerability in KeySight N6854A and N6841A RF.
This vulnerability is due to Java serialization issues when processing requests. A remote unauthenticated attacker can exploit this vulnerability by sending a crafted request. Successful exploitation would result in arbitrary code execution with SYSTEM privileges.
KeySight N6854A and N6841A RF 2.3.0 and prior
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.