CVE-2022-45979 is a high-severity stack overflow vulnerability identified in the Tenda AX12 router firmware version v22.03.01.21_CN. The vulnerability arises from improper handling of the 'ssid' parameter in the HTTP endpoint /goform/fast_setting_wifi_set. Specifically, the stack overflow occurs when the input to the 'ssid' parameter exceeds the expected buffer size, leading to memory corruption on the stack. This type of vulnerability is classified under CWE-787 (Out-of-bounds Write). Exploitation of this flaw requires no authentication and no user interaction, as the vulnerable endpoint is accessible remotely over the network. The CVSS 3.1 base score is 7.5, indicating a high severity level, with the vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. This means the attack can be launched remotely over the network with low attack complexity, no privileges, and no user interaction, but the impact is limited to availability (denial of service) without direct confidentiality or integrity compromise. There is no public evidence of active exploitation in the wild, and no official patches or vendor advisories have been linked to this vulnerability at the time of publication. The lack of vendor and product metadata beyond the firmware version and model limits detailed attribution, but the affected device is a consumer-grade Wi-Fi 6 router widely used in some markets. The vulnerability could allow an attacker to crash the device remotely, causing denial of service and potentially forcing a reboot or requiring manual intervention to restore network connectivity.

For European organizations, the impact of this vulnerability primarily concerns network availability and operational continuity. Organizations relying on Tenda AX12 routers for critical network infrastructure or as part of their office or branch connectivity may experience service disruptions if targeted. Although the vulnerability does not directly compromise confidentiality or integrity, denial of service on network routers can lead to significant operational downtime, loss of productivity, and potential cascading effects on dependent services. Small and medium enterprises (SMEs) and home office environments using this router model are particularly at risk due to typically less rigorous network segmentation and security monitoring. Additionally, sectors with high availability requirements, such as financial services, healthcare, and public administration, could face challenges if these devices are deployed within their network perimeter. The absence of known exploits reduces immediate risk, but the ease of exploitation and remote accessibility mean that attackers could develop exploits rapidly. Given the router's consumer orientation, it is less likely to be deployed in large-scale enterprise environments, but its presence in smaller offices and home networks connected to corporate VPNs could serve as a foothold for lateral movement if exploited.

1. Immediate mitigation should focus on network-level controls: restrict access to the router's management interface by implementing firewall rules that limit inbound connections to trusted IP addresses only. 2. Disable remote management features on the Tenda AX12 router if enabled, especially access to HTTP endpoints like /goform/fast_setting_wifi_set. 3. Monitor network traffic for unusual requests targeting the /goform/fast_setting_wifi_set endpoint or anomalous spikes in router reboots or availability issues. 4. Where possible, replace affected Tenda AX12 devices with alternative routers from vendors with active security support and patch management. 5. If replacement is not feasible, isolate the vulnerable routers on segmented network zones with strict access controls to minimize potential impact. 6. Engage with Tenda support channels to obtain firmware updates or patches addressing this vulnerability; if none are available, advocate for vendor response. 7. Implement intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect attempts to exploit the stack overflow via malformed 'ssid' parameters. 8. Educate network administrators about this vulnerability and encourage regular audits of router firmware versions and configurations to ensure compliance with security best practices.