This indicates an attack attempt to exploit a Buffer Overflow vulnerability in Tenda AC15 Router.
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.
Tenda AC15 Router V15.03.1.16 and earlier
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently, we are unaware of any vendor supplied patch for this issue.