A critical stack-based buffer overflow in Tenda W3 firmware version 1.0.0.3(2204) enables remote attackers to execute arbitrary code or cause a system crash.

This vulnerability is a stack-based buffer overflow (CWE-121) located in the formWifiMacFilterGet function of the /goform/WifiMacFilterGet endpoint. While the CVSS vector indicates low privilege requirements, the flaw allows an authenticated attacker to perform memory corruption by manipulating the wl_radio or index POST parameters.

Successful exploitation of this vulnerability can lead to a complete compromise of the affected Tenda W3 device, potentially allowing an attacker to gain unauthorized control over network traffic or disrupt communications. Given the CVSS score of 8.8, this vulnerability represents a high risk to organizational infrastructure, as it could facilitate further lateral movement or result in significant service unavailability.

Immediate Action: There is currently no official vendor patch available; users should restrict administrative access to the device to trusted management interfaces only.

Proactive Monitoring: Security teams should monitor network traffic for anomalous POST requests directed at the /goform/WifiMacFilterGet endpoint, specifically looking for unusually large payloads in the wl_radio or index parameters.

Compensating Controls: Implement Web Application Firewall (WAF) rules to inspect and filter incoming traffic for oversized inputs on the identified vulnerable endpoint to prevent buffer overflow attempts.

Public Exploit Available: Yes, a functional proof-of-concept is available via the researcher-published GitHub repository linked in the CVE record.

Given the high severity of this stack-based buffer overflow and the availability of a public proof-of-concept, organizations must treat this vulnerability with urgency. In the absence of a vendor-provided patch, administrators should aggressively isolate affected devices from external network exposure and employ strict access control lists to mitigate potential exploitation attempts until a firmware update is released.