A critical stack-based buffer overflow vulnerability in Tenda F456 routers poses a significant risk of remote code execution for authenticated users.

This vulnerability occurs in the formWrlsafeset function within the /goform/AdvSetWrlsafeset endpoint, where the mit_ssid parameter is processed without adequate length validation. This memory corruption flaw can be triggered by an authenticated user to overwrite the stack, potentially leading to denial of service or remote code execution.

Successful exploitation allows an attacker to gain unauthorized control over the affected network device, which may lead to complete compromise of local network traffic or permanent denial of service. Given the high CVSS score of 8.8, this flaw represents a severe threat to infrastructure integrity and data confidentiality.

Immediate Action: Contact the vendor for firmware updates, as no official patch is currently identified for this specific version. If no update is available, restrict management interface access to trusted administrative networks only.

Proactive Monitoring: Monitor device logs for unusual POST requests directed at the /goform/AdvSetWrlsafeset endpoint and watch for abnormal system reboots or service crashes.

Compensating Controls: Implement strict network access control lists to prevent unauthorized users from reaching the administrative web interface of the router.

Public Exploit Available: Yes, a published proof-of-concept exists, as documented in the research write-up by Li Tengzheng.

The presence of a publicly available proof-of-concept significantly lowers the barrier for exploitation. Organizations utilizing Tenda F456 hardware must treat this vulnerability with high urgency, isolating vulnerable devices from the public internet until a vendor-supplied patch is applied.