This indicates an attack attempt to exploit a remote Code Execution vulnerability in Microsoft HTTP protocol stack.
The vulnerability is due to an improper boundary check condition in the protocol 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.
Windows Server 2012 and Windows Server 2012 R2
Windows Server 2008 R2
Windows 8 and Windows 8.1
Server Core installation option
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.