A critical stack-based buffer overflow in Tenda FH451 firmware version 1.0.0.9 poses a significant risk of remote code execution.

The vulnerability resides in the WrlclientSet function within the /goform/WrlclientSet endpoint. An attacker with low-level privileges can supply an overly long string to the GO parameter, which is processed without sufficient length checks, leading to a stack-based buffer overflow.

Successful exploitation of this vulnerability allows an unauthenticated or low-privileged remote attacker to execute arbitrary code or crash the device, leading to a complete denial of service. Given the CVSS score of 8.8, this represents a high-severity threat that could result in total compromise of the network appliance and unauthorized access to internal traffic.

Immediate Action: Since no official patch is currently identified, administrators should restrict access to the device management interface and block external access to the /goform/WrlclientSet endpoint at the network perimeter.

Proactive Monitoring: Monitor device logs for unusual POST requests directed at the /goform/WrlclientSet endpoint or unexpected service restarts that may indicate crash attempts.

Compensating Controls: Implement a Web Application Firewall (WAF) rule to inspect and drop requests containing excessively long strings in the GO parameter to mitigate the overflow vector.

Public Exploit Available: Yes, a published proof-of-concept exists in the researcher write-up at the provided GitHub reference.

The severity of this remote code execution vulnerability necessitates immediate attention. Organizations utilizing Tenda FH451 routers should prioritize isolating these devices from the public internet and applying vendor firmware updates as soon as they become available to neutralize this critical exposure.