This indicates an attack attempt to exploit a Denial of Service vulnerability in Embedthis Goahead Webserver.
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 cause a denial of service condition on the affected system.
Embedthis Goahead Webserver 3.1.3-0 and prior
Denial of Service: Remote attackers can crash vulnerable systems or services
Apply the most recent upgrade or patch from the vendor.