A critical buffer overflow vulnerability in Tenda F456 firmware version 1.0.0.5 poses a significant risk of remote code execution.

This is a stack-based buffer overflow vulnerability triggered by improper length validation within the fromaddressNat function. An authenticated attacker can send a crafted POST request to the /goform/addressNat endpoint to corrupt memory and potentially execute arbitrary code on the device.

The CVSS score of 8.8 indicates a high-severity risk, primarily due to the potential for total system compromise. Successful exploitation allows an attacker to gain full control over the network device, which can be leveraged for unauthorized data access, network interception, or persistent presence within the local area network.

Immediate Action: As no official patch is currently available, administrators should restrict management interface access to trusted IP addresses only and disable remote administration features until the vendor releases a firmware update.

Proactive Monitoring: Review web access logs for unusual POST requests directed at the /goform/addressNat endpoint, particularly those containing excessively long parameter strings in the mitInterface field.

Compensating Controls: Deploy a network-level firewall or Web Application Firewall (WAF) rule to drop HTTP requests containing abnormally large payloads targeted at the vulnerable management URI.

Public Exploit Available: Yes, a functional proof-of-concept is documented in the technical write-up provided by the researcher.

Given the availability of a public proof-of-concept and the potential for remote code execution, this vulnerability represents an urgent threat to network integrity. Organizations utilizing the Tenda F456 should implement immediate network segmentation or restrictive access controls to mitigate exposure while awaiting an official firmware patch from the vendor.