CVE-2021-31755: Tenda AC11 Router Stack Buffer Overflow Vulnerability

CVE-2021-31755 is a stack buffer overflow vulnerability in Tenda AC11 routers, specifically in the /goform/setmac functionality. An attacker can send a specially crafted POST request to trigger the overflow and execute arbitrary code on the device. This vulnerability has been observed to be exploited in the wild, indicating active threat usage. No vendor advisory or patch information is available in the provided data.

Successful exploitation allows remote code execution on the affected Tenda AC11 router, potentially leading to full compromise of the device. This can enable attackers to control the router, intercept or manipulate network traffic, or use the device as a foothold for further attacks.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is available, restrict access to the router's management interface and monitor for suspicious POST requests targeting /goform/setmac.