A stack-based buffer overflow vulnerability in Tenda i3 devices enables authenticated attackers to potentially execute arbitrary code or cause a system crash.

This vulnerability is a stack-based buffer overflow located in the formwrlSSIDset function within the /goform/wifiSSIDset endpoint. The flaw is triggered by passing a maliciously crafted GO parameter, which requires the attacker to be an authenticated user.

Successful exploitation of this vulnerability can lead to a complete compromise of the affected Tenda i3 device, potentially allowing an attacker to execute arbitrary code or cause a persistent denial-of-service condition. Given the CVSS score of 8.8, this represents a high-severity risk that could expose internal network segments or disrupt critical connectivity if the device is used in a business environment.

Immediate Action: As no official patch is currently confirmed, administrators should restrict access to the device management interface to trusted administrative subnets only. If the device functionality is not mission-critical, consider isolating the hardware from the network until the vendor provides a firmware update.

Proactive Monitoring: Monitor device logs for unusual POST requests directed at the /goform/wifiSSIDset URI, particularly those containing abnormally long strings or unexpected characters in the GO parameter.

Compensating Controls: Implement Web Application Firewall (WAF) rules or network-level access control lists (ACLs) to validate the length of parameters sent to the /goform/wifiSSIDset endpoint.

Public Exploit Available: Yes, a functional proof-of-concept exists as documented in the researcher's GitHub repository.

Given the availability of a public proof-of-concept and the potential for code execution, this vulnerability poses a significant risk to Tenda i3 deployments. Organizations should immediately restrict network access to the affected devices and monitor for vendor releases to patch the underlying memory corruption flaw.