A critical heap-based buffer overflow vulnerability in Tenda M3 routers allows remote authenticated attackers to execute arbitrary code or cause system crashes.

The vulnerability exists in the formSetRemoteInternetLanInfo function, where lack of input sanitization on network configuration parameters leads to heap-based buffer overflows. The attack requires an authenticated user to provide a specific cookie containing a device UID and send a crafted HTTP POST request to the /goform/setInternetLanInfo endpoint.

The exploitation of this vulnerability can lead to unauthorized remote code execution, potentially granting an attacker full control over the affected networking hardware. Given the CVSS score of 8.8, this represents a high-severity risk that could lead to complete device compromise, network traffic interception, or permanent denial of service, severely impacting business operations.

Immediate Action: As no official patch is currently available, administrators should immediately restrict access to the web management interface of the Tenda M3 to trusted internal networks only.

Proactive Monitoring: Monitor device logs for anomalous POST requests directed at the /goform/setInternetLanInfo endpoint and watch for unexpected device reboots or instability.

Compensating Controls: Deploy firewall rules to block unauthorized external access to the management interface and utilize an intrusion detection system to monitor for malformed POST parameters targeting this specific service.

Public Exploit Available: Yes, a published proof-of-concept exists, as documented in the researcher write-up referenced by the CVE record.

Due to the availability of a public proof-of-concept and the potential for remote code execution, this vulnerability poses a significant risk to organizational infrastructure. Administrators must prioritize isolating affected Tenda M3 devices from public-facing exposure and monitor for vendor updates to apply the necessary security patches as soon as they are released.