A buffer overflow vulnerability in Tenda AC6 V2 routers allows unauthenticated remote attackers to crash the device, leading to a complete Denial of Service.

This vulnerability is a buffer overflow occurring within the speed_dir parameter of the SetSpeedWan function. It can be triggered by an unauthenticated attacker sending a crafted input to the device, resulting in a system crash.

Successful exploitation of this flaw results in a Denial of Service, which effectively takes the network device offline. Given the CVSS score of 7.5, this high severity risk could disrupt critical business operations, communication, and connectivity for all users reliant on the affected router.

Immediate Action: Since a specific patch version is currently unknown, administrators should isolate the affected devices from public-facing network segments and restrict management access to trusted internal IP ranges only.

Proactive Monitoring: Monitor device logs for unusual traffic patterns or recurring system reboots that may indicate automated attempts to trigger the buffer overflow.

Compensating Controls: Deploy a network-level firewall or Intrusion Prevention System (IPS) to filter malformed packets targeting the router management interface, effectively acting as a virtual patch.

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

This vulnerability poses a significant risk to network availability because it requires no authentication to execute. Security teams must prioritize restricting access to the management interface of the Tenda AC6 V2 until the vendor releases a firmware update that addresses the buffer overflow in the SetSpeedWan function.