This indicates an attack attempt to exploit a Directory Traversal Vulnerability in KeySight N6854A and N6841A RF.
This vulnerability is due to incomplete input sanitization in Java class UserFirmwareRequestHandler. A remote unauthenticated attacker can exploit this vulnerability by sending a crafted request. Successful exploitation could read arbitrary files on the target server under the security context of the SYSTEM.
KeySight N6854A and N6841A RF 2.3.0 and prior
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Apply the most recent upgrade or patch from the vendor.