A stack-based buffer overflow vulnerability in the Tenda F453 router enables remote attackers to achieve arbitrary code execution or cause a denial of service.

The flaw occurs in the fromPptpUserAdd function within the /goform/PPTPDClient endpoint, where user-supplied username and opttype parameters are processed without sufficient length validation. This allows an authenticated attacker to trigger a stack-based buffer overflow via a specially crafted HTTP POST request.

Successful exploitation of this vulnerability poses a severe risk to network integrity and availability. An attacker could gain unauthorized remote code execution capabilities on the affected device, potentially leading to full system compromise or a persistent denial of service that disrupts critical connectivity. Given the CVSS score of 8.8, this vulnerability is classified as High severity and requires immediate attention to prevent unauthorized access to the network infrastructure.

Immediate Action: Since a specific patch version is not currently identified, users should restrict administrative access to the management interface and verify if the vendor has released a firmware update via the official Tenda support website.

Proactive Monitoring: Security teams should monitor network traffic for anomalous HTTP POST requests directed toward the /goform/PPTPDClient endpoint and review device logs for signs of repeated crashes or unauthorized configuration changes.

Compensating Controls: Deploy a Web Application Firewall or network-level access control list to block unauthorized access to the router management interface, effectively isolating the vulnerable function from external reach.

Public Exploit Available: Yes, a proof-of-concept is documented in the technical write-up published on the Litengzheng GitHub repository.

The presence of a public proof-of-concept significantly elevates the risk of exploitation for this high-severity vulnerability. Administrators must prioritize isolating the vulnerable Tenda F453 devices from the public internet and apply any available firmware updates from the vendor as soon as they are made available to mitigate the risk of remote code execution.