Stack-based Buffer Overflow in Tenda W12 cgiSysTimeInfoSet

Successful exploitation can crash the affected httpd process or the device, resulting in denial of service. Because the flaw is a stack-based buffer overflow in a remotely reachable management component, exploitation may also enable arbitrary code execution in the security context of the vulnerable service, which could lead to full compromise of the device, including loss of confidentiality, integrity, and availability.

Until a fixed firmware release is available, do not expose the device management interface to the internet or untrusted networks. Restrict access to the web administration service to trusted management hosts only using network ACLs, firewall rules, or VPN-based administration. Disable remote administration if not operationally required, segment affected devices from untrusted networks, and monitor for suspicious requests targeting the cgiSysTimeInfoSet endpoint or anomalous crashes/restarts of /bin/httpd.

Upgrade Tenda W12 devices from firmware 3.0.0.7(4763) to a vendor-fixed release if one is available. If Tenda has issued updated firmware or hotfix guidance, apply it across all exposed devices and verify the vulnerable /bin/httpd component is replaced. After upgrading, validate that the management interface no longer accepts malformed sec values that trigger the overflow.