A critical stack-based buffer overflow in Tenda AC7 firmware version 15.03.06.44 poses a significant risk of remote code execution and system instability.

This vulnerability is a stack-based buffer overflow (CWE-121) occurring in the saveAutoQos function, triggered when an oversized enable parameter is processed. While the CVSS vector indicates that low privileges are required, the flaw allows an attacker to corrupt memory and potentially disrupt service or execute code on the device.

The exploitation of this buffer overflow can lead to complete device compromise or persistent denial of service, significantly impacting network availability for users relying on the Tenda AC7 router. With a CVSS score of 8.8, this vulnerability is categorized as high severity due to its potential for total impact on confidentiality, integrity, and availability. Unauthorized access to network infrastructure hardware can facilitate lateral movement or further exploitation of connected internal systems.

Immediate Action: As no official patch is currently identified, users should restrict administrative access to the router interface and ensure the device is not exposed to the public internet. Monitor vendor support pages for firmware updates that address this specific memory corruption vulnerability.

Proactive Monitoring: Review device access logs for suspicious POST requests directed at /goform/saveAutoQos or /goform/getAdvanceStatus. Monitor the device for unexpected reboots or service instability that may indicate active exploitation attempts.

Compensating Controls: Implement network-level access control lists (ACLs) to limit access to the router's management interface to trusted internal IP addresses only. Deploy a firewall or intrusion detection system capable of inspecting and blocking malformed HTTP requests containing excessively long parameters.

Public Exploit Available: Yes, a published proof-of-concept exists and is attributed to the technical write-up provided in the referenced GitHub repository.

Given the availability of a public proof-of-concept and the nature of the vulnerability, the risk to Tenda AC7 deployments is elevated. Administrators must isolate the management interface of the affected hardware immediately and monitor for vendor-provided firmware updates to remediate the underlying memory corruption flaw.