Outbreak Alert: HTTP/2 Rapid Reset Attack and Mitigation

1. In FortiWeb -> Web Protection -> Protocol -> HTTP, select Create New or Edit an existing entry. (The example in this article is made with Create New).
   
   

2. In the new window, input a name. Enable HTTP/2 Max Requests and set an action as needed (the default action is Alert), then select OK.
   
   

3. Check the new HTTP Protocol Constraints were created successfully. The name used here is http2_test.
                                             

4. Under FortiWeb -> Policy -> Web Protection Profile, edit the corresponding profile.
                                    

5. Select the newly added profile (http2_test in this example) in HTTP Protocol Constraints and select OK.

To apply it on FortiAppSec Cloud:

• Navigate to the desired Application.
• Navigate to Application Name -> Access Rules -> Request Limits, then set 'HTTP/2 Max Requests' to 'ON' and 'Number of HTTP/2 Max Requests' to '1000'.