A critical stack-based buffer overflow vulnerability in Tenda F453 routers allows authenticated attackers to execute arbitrary code or cause a system crash.

This vulnerability resides in the sub_3C6C0 function within the /goform/QuickIndex endpoint. It occurs when the application fails to perform length checks on the PPPOEPassword argument during specific configuration requests, allowing an authenticated user to overwrite the stack memory.

Successful exploitation of this flaw can lead to a complete compromise of the affected router, granting an attacker the ability to execute remote code with high privileges. This could result in unauthorized network access, data interception, or persistent system downtime, significantly impacting the availability and integrity of the local network infrastructure. The CVSS score of 8.8 reflects the high severity of this remote execution capability.

Immediate Action: Since a specific patch version is not currently listed, administrators should restrict management interface access to trusted IP addresses only and monitor for vendor firmware releases.

Proactive Monitoring: Security teams should monitor network traffic for anomalous POST requests directed at the /goform/QuickIndex endpoint, particularly those containing excessively long strings in the PPPOEPassword field.

Compensating Controls: Deploy a Web Application Firewall (WAF) or an Intrusion Prevention System (IPS) rule to inspect and block HTTP traffic containing oversized payloads targeting the vulnerable form parameters.

Public Exploit Available: Yes, a published proof-of-concept exists and is attributed to the technical write-up hosted on GitHub by the vulnerability researcher.

Given the availability of a public proof-of-concept and the potential for remote code execution, this vulnerability poses a significant risk to network security. Organizations utilizing Tenda F453 devices should prioritize isolating these units from the public internet and verify firmware status with the vendor immediately. Applying future manufacturer security updates as soon as they become available is essential to remediate this flaw.