This indicates an attack attempt to exploit a command execution vulnerability in Cisco WebEx Chrome Extension.
The vulnerability is caused by lacking of checking the message sent by "cwcsf-nativemsg-iframe-43c85c0d-d633-af5e-c056-32dc7efc570b.html". A remote attacker may be able to exploit this to execute arbitrary code within the context of the application.
Cisco WebEx Extension for Chrome before version 1.0.3
System Compromise: Remote attackers can gain control of vulnerable systems.
Update the extension to the latest version.