CVE-2025-7544 is a critical stack-based buffer overflow vulnerability identified in the Tenda AC1206 router, specifically in firmware version 15.03.06.23. The vulnerability resides in the function formSetMacFilterCfg within the /goform/setMacFilterCfg endpoint. This function processes the deviceList argument, which, when manipulated maliciously, leads to a stack-based buffer overflow condition. Such a vulnerability can allow an attacker to overwrite the stack memory, potentially enabling arbitrary code execution or causing a denial of service (DoS) by crashing the device. The vulnerability is remotely exploitable without requiring user interaction or prior authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The CVSS 4.0 base score is 8.7, categorizing it as a high-severity issue. Although no public exploit is currently known to be actively used in the wild, the exploit details have been disclosed, increasing the risk of exploitation by threat actors. The vulnerability impacts the confidentiality, integrity, and availability of the affected device, as successful exploitation could allow attackers to take control of the router, intercept or manipulate network traffic, or disrupt network connectivity. The lack of available patches at the time of disclosure further exacerbates the risk for affected users. Given the critical nature of the router in network infrastructure, exploitation could have cascading effects on connected devices and organizational networks.

For European organizations, the impact of this vulnerability is significant due to the widespread use of Tenda networking equipment in small to medium enterprises and residential environments. Compromise of the Tenda AC1206 router could lead to unauthorized access to internal networks, interception of sensitive communications, and disruption of business operations through denial of service. This is particularly concerning for organizations relying on these routers for perimeter security or remote access. The vulnerability could be leveraged by attackers to establish persistent footholds within networks, facilitating further lateral movement and data exfiltration. Additionally, critical infrastructure sectors that utilize such routers for connectivity may face operational disruptions. The remote and unauthenticated nature of the exploit increases the attack surface, making it easier for cybercriminals or state-sponsored actors to target vulnerable devices across Europe. The absence of patches at disclosure time means organizations must rely on mitigation strategies to reduce exposure, increasing operational complexity and risk.

1. Immediate network segmentation: Isolate Tenda AC1206 devices from critical network segments to limit potential lateral movement in case of compromise. 2. Disable or restrict access to the /goform/setMacFilterCfg endpoint if possible, using firewall rules or router configuration settings to prevent unauthorized remote requests. 3. Monitor network traffic for unusual or malformed requests targeting the deviceList parameter or the /goform/setMacFilterCfg endpoint, employing intrusion detection/prevention systems (IDS/IPS) with custom signatures. 4. Implement strict access controls and limit management interface exposure to trusted IP addresses or VPN connections only. 5. Regularly audit and inventory network devices to identify all instances of Tenda AC1206 routers and verify firmware versions. 6. Engage with Tenda support channels to obtain firmware updates or patches as soon as they become available and plan for prompt deployment. 7. Consider temporary replacement or upgrade of vulnerable devices in high-risk environments to models with no known vulnerabilities. 8. Educate IT staff about the vulnerability and ensure incident response plans include steps for potential exploitation scenarios involving network infrastructure devices.