A critical vulnerability in Tenda AC6 routers allows unauthenticated attackers to remotely crash the device, leading to a permanent denial of service.

The device suffers from multiple buffer overflow vulnerabilities within the openSchedWifi function. These flaws are reachable by unauthenticated attackers who can inject malicious payloads into the schedStartTime and schedEndTime parameters to cause a system crash.

The CVSS score of 7.5 indicates a high severity risk, primarily due to the ease of exploitation and the potential for a complete denial of service. For organizations relying on these routers for network connectivity, a successful attack would result in immediate operational downtime, disrupting business processes and requiring manual intervention to restore service.

Immediate Action: Since no official patch is currently available, immediately restrict access to the device management interface by ensuring it is not exposed to the public internet.

Proactive Monitoring: Monitor network traffic for unusual payloads directed toward the router management interface and investigate any unexpected device reboots or service interruptions.

Compensating Controls: Deploy a firewall or Access Control List to limit management access to known, trusted internal IP addresses only, effectively neutralizing the remote vector for unauthenticated attackers.

Public Exploit Available: Yes, a published proof-of-concept exists as documented in the technical write-up provided by the vulnerability researcher.

Given the lack of a vendor-provided patch, users must treat this device as high-risk and prioritize network segmentation. Ensure that the Tenda AC6 web interface is strictly isolated from external networks to prevent remote exploitation. Monitor vendor channels closely for firmware updates and apply them immediately upon release to remediate the underlying buffer overflow flaw.