This indicates an attack attempt to exploit a Remote Code Execution vulnerability in the Wserver component of ABB MicroSCADA.
The vulnerability is due to a design flaw when the vulnerable software handles user controlled data. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted request.
ABB MicroSCADA Prior to 9.3 FP2 Hotfix 2
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.