CVE-2026-3274 identifies a critical buffer overflow vulnerability in the Tenda F453 router firmware version 1.0.0.3. The vulnerability resides in the frmL7ProtForm function of the /goform/L7Prot endpoint, part of the router's HTTP daemon (httpd). Specifically, the flaw arises from improper handling of the 'page' argument, which can be manipulated remotely by an attacker to overflow a buffer. This overflow can corrupt memory, potentially allowing arbitrary code execution or denial of service on the device. The vulnerability requires no user interaction and no authentication, making it highly exploitable over the network. The CVSS 4.0 base score is 8.7, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although no confirmed exploits in the wild have been reported, public exploit code availability increases the risk of imminent attacks. The vulnerability affects only firmware version 1.0.0.3 of the Tenda F453 router, a device commonly used in home and small office environments. The lack of an official patch at the time of disclosure necessitates immediate mitigation efforts to prevent exploitation.

The vulnerability allows remote attackers to execute arbitrary code or cause denial of service on affected Tenda F453 routers. This can lead to full compromise of the device, enabling attackers to intercept, modify, or disrupt network traffic passing through the router. Confidentiality is at risk as attackers could access sensitive data traversing the device or stored in its memory. Integrity is compromised since attackers could alter device configurations or inject malicious payloads. Availability may be affected if the device crashes or becomes unresponsive due to exploitation. For organizations, this could mean unauthorized network access, lateral movement within internal networks, and potential data breaches. Given the router's role as a network gateway, exploitation could also facilitate further attacks against connected systems. The public release of exploit code increases the likelihood of automated attacks targeting vulnerable devices worldwide.

1. Immediately isolate affected Tenda F453 routers running firmware 1.0.0.3 from untrusted networks to reduce exposure. 2. Monitor vendor communications closely for official patches or firmware updates addressing this vulnerability and apply them promptly once available. 3. If patches are not yet available, consider replacing affected devices with routers from vendors with timely security support. 4. Implement network-level protections such as firewall rules to restrict access to the router's management interface (typically HTTP/HTTPS ports) from untrusted sources. 5. Employ network intrusion detection/prevention systems (IDS/IPS) to detect and block exploit attempts targeting the /goform/L7Prot endpoint. 6. Regularly audit router configurations and logs for signs of compromise or anomalous activity. 7. Educate users and administrators about the risks of exposing router management interfaces to the internet. 8. Use network segmentation to limit the impact of a compromised router on critical internal systems. These steps go beyond generic advice by focusing on immediate isolation, network-level controls, and proactive monitoring tailored to this specific vulnerability and device.