This indicates an attack attempt to exploit a Remote Code Execution vulnerability in H2 Database.
The vulnerability is due to insufficient validation of user supplied inputs in the application. A remote attacker may be able to exploit this to execute arbitrary remote code within the context of the application, via a crafted HTTP request.
H2 1.4.197, as used in Datomic before 0.9.5697 and other products.
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.