A critical stack overflow vulnerability in Tenda AC18 routers could allow an unauthenticated attacker to cause a denial of service condition.

This vulnerability is a stack-based buffer overflow triggered by sending a specially crafted value to the mac parameter within the fromAdvSetMacMtuWan function. The attack can be executed by an unauthenticated user over the network.

Successful exploitation of this vulnerability results in a denial of service, rendering the affected network device unresponsive. Given the CVSS score of 7.5, this high severity flaw poses a significant risk to business continuity, as compromised routing equipment can disrupt all internal and external network traffic, leading to operational downtime.

Immediate Action: Since a specific patch version is not currently listed, administrators should contact Tenda support for firmware updates or restrict access to the device management interface from untrusted networks.

Proactive Monitoring: Monitor device logs for recurring crashes or unexpected restarts that may indicate attempted exploitation of the stack overflow.

Compensating Controls: Implement firewall rules to restrict access to the device management interface, ensuring that only authorized administrative IP addresses can reach the affected service.

Public Exploit Available: No (Exploit available: false)

The vulnerability presents a credible risk of service disruption for Tenda AC18 users. Organizations should prioritize isolating the affected hardware from the public internet and await official vendor guidance on a permanent firmware update to resolve the buffer overflow.