A critical stack-based buffer overflow vulnerability in Tenda AC18 routers could allow remote attackers to achieve unauthorized code execution.

The device is susceptible to a stack-based buffer overflow due to improper length validation within the /goform/WifiMacFilterSet endpoint. An attacker with low-level privileges can trigger this memory corruption by sending a crafted POST request containing an oversized wifi_chkHz parameter.

Successful exploitation of this vulnerability allows an attacker to execute arbitrary code on the affected router. This level of compromise poses a severe risk to organizational network integrity, as it grants the attacker a foothold to intercept traffic, pivot into internal network segments, or disrupt critical connectivity. With a CVSS score of 8.8, this vulnerability is classified as High severity and requires immediate attention to prevent potential exploitation.

Immediate Action: Users should immediately check the Tenda support website for firmware updates addressing this vulnerability and apply them to the affected AC18 devices.

Proactive Monitoring: Security teams should monitor network traffic for anomalous POST requests directed at the /goform/WifiMacFilterSet or /goform/WifiExtraSet endpoints.

Compensating Controls: Deploy a Web Application Firewall or router-level access control list to restrict access to the web management interface to trusted internal IP addresses only.

Public Exploit Available: Yes, a published proof-of-concept exists as detailed in the technical write-up provided by the vulnerability researcher.

Given the availability of a public proof-of-concept and the potential for remote code execution, this vulnerability represents a significant security risk to Tenda AC18 users. Administrators must prioritize the application of vendor patches as soon as they become available. If a patch cannot be applied immediately, restrict administrative access to the device management interface to minimize the attack surface.