CVE-2025-15218 is a buffer overflow vulnerability identified in the Tenda AC10U router firmware versions 15.03.06.48 and 15.03.06.49. The vulnerability resides in the function fromadvsetlanip within the /goform/AdvSetLanip component, which handles POST request parameters. Specifically, the lanMask argument is improperly validated, allowing an attacker to send a crafted POST request that triggers a buffer overflow condition. This flaw can be exploited remotely over the network without requiring authentication or user interaction, making it highly accessible to attackers. The buffer overflow can lead to memory corruption, potentially enabling remote code execution or causing a denial of service by crashing the device. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no required privileges. Although no active exploitation has been reported in the wild, a public exploit is available, increasing the likelihood of future attacks. The vulnerability affects a widely used consumer and small business router model, which is often deployed in home and office environments, making it a significant risk vector for network compromise and lateral movement. The lack of an official patch at the time of disclosure necessitates immediate mitigation strategies to reduce exposure.

For European organizations, this vulnerability poses a substantial risk due to the widespread use of Tenda AC10U routers in both consumer and small to medium business environments. Successful exploitation could allow attackers to gain unauthorized remote control over affected routers, leading to interception or manipulation of network traffic, deployment of malware, or pivoting into internal networks. This compromises the confidentiality and integrity of sensitive data and can disrupt business operations through denial of service. The vulnerability's remote exploitability without authentication increases the attack surface, especially for organizations with exposed management interfaces or insufficient network segmentation. Given the critical role routers play as network gateways, exploitation could facilitate large-scale attacks or espionage campaigns targeting European entities. The potential for widespread impact is heightened by the availability of a public exploit, which lowers the barrier for threat actors to weaponize this vulnerability.

1. Immediate network-level mitigation: 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 AC10U routers if not required, reducing exposure to external attackers. 3. Monitor network traffic for unusual POST requests targeting /goform/AdvSetLanip or anomalous behavior indicative of exploitation attempts. 4. Segment networks to isolate vulnerable routers from critical infrastructure and sensitive data environments, minimizing lateral movement risks. 5. Engage with Tenda support channels to obtain official firmware updates or patches as soon as they become available and prioritize their deployment. 6. If patching is delayed, consider temporary replacement of vulnerable devices with alternative hardware or firmware known to be secure. 7. Educate IT staff about this vulnerability and the importance of securing router management interfaces. 8. Employ intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect attempts to exploit this buffer overflow. 9. Regularly audit router configurations to ensure adherence to security best practices and promptly remediate deviations.