This indicates an attack attempt to exploit an Arbitrary File Write Vulnerability in Lucee Server.
The vulnerability is due to improper handling of a craft HTTP request.
Lucee Server version 5.3.5.00 to version 188.8.131.52
Lucee Server version 5.3.6.00 to version 184.108.40.206
Lucee Server version 5.3.7.00 to version 220.127.116.11
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.