A critical stack-based buffer overflow vulnerability in Tenda AC7 routers allows authenticated attackers to trigger remote code execution or system instability.

The vulnerability exists in the /goform/setNotUpgrade interface, where the newVersion parameter fails to perform adequate input size validation. This allows a low-privileged authenticated attacker to overflow a stack buffer when the value is later retrieved by the /goform/GetRouterStatus routine.

Successful exploitation of this flaw can lead to a complete compromise of the router, including unauthorized remote code execution. Given the CVSS score of 8.8, this represents a high-severity risk that could lead to network-wide interception, data exfiltration, or the permanent denial of service of critical infrastructure.

Immediate Action: Users should visit the official Tenda support website to check for and apply the latest firmware updates that resolve this memory corruption flaw.

Proactive Monitoring: Security teams should monitor network traffic for suspicious POST requests directed at /goform/setNotUpgrade and unusual router status queries.

Compensating Controls: Deploy a Web Application Firewall or network-level access control list to restrict access to the web management interface of the router to authorized management workstations only.

Public Exploit Available: Yes, a functional proof-of-concept exploit is available via the researcher's technical write-up on GitHub.

The severity of this vulnerability, combined with the availability of a public proof-of-concept, necessitates immediate action. Administrators must prioritize patching the affected Tenda AC7 devices to the latest available firmware version to mitigate the risk of remote code execution and unauthorized system access.