This indicates an attack attempt to exploit a Remote Command Execution vulnerability in Palo Alto GlobalProtect server.
The vulnerability is due to insufficient sanitization of user supplied inputs. A remote attacker may be able to exploit this to execute arbitrary commands within the context of the application, via a crafted request.
PAN-OS 7.1.18 and earlier
PAN-OS 8.0.11-h1 and earlier
PAN-OS 8.1.2 and earlier
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to the vendor's advisory for updates: