This indicates an attack attempt to exploit a Code Execution vulnerability in Xfinity Web Gateway.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application when handling a crafted HTTP request. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted HTTP request.
Xfinity Web Gateway
System Compromise: Remote attackers can execute arbitrary code on vulnerable systems.
Currently we are unaware of any vendor supplied patch or updates available for this issue.