This indicates an attempt to access ReDuh HTTP Tunnel.
ReDuh creates a HTTP proxy to tunnel data in and out of a network. It is often used to bypass firewall policy that only allows HTTP traffics. ReDuh can pass other TCP sessions such as RDP and SSH through the HTTP tunnel.
All web servers
System Compromise: Remote attackers can gain control of vulnerable systems.
Monitor the traffic from the network for any suspicious activity.
Look for a suspicious PHP, ASP, or JSP drop file on the web server, based on the IPS log entry.