CVE-2025-11297 is a high-severity buffer overflow vulnerability identified in the Belkin F9K1015 router, specifically in firmware version 1.00.10. The vulnerability arises from improper handling of input parameters in the /goform/formSetLanguage endpoint, where manipulation of the 'webpage' argument can trigger a buffer overflow condition. This flaw allows an unauthenticated remote attacker to send specially crafted requests to the device, causing memory corruption. The vulnerability does not require user interaction or prior authentication, making it remotely exploitable over the network. The buffer overflow can potentially lead to arbitrary code execution, denial of service, or system compromise. The CVSS 4.0 score of 8.7 reflects the critical nature of the vulnerability, with network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Although the vendor was notified early, no response or patch has been issued, and a public exploit has been released, increasing the risk of exploitation. The affected product is a widely used consumer and small office router, which may be deployed in various environments including European organizations. The lack of vendor remediation and public exploit availability heightens the urgency for mitigation.

For European organizations, this vulnerability poses a significant risk to network security and operational continuity. Exploitation could allow attackers to gain control over affected routers, enabling interception or manipulation of network traffic, insertion of malicious payloads, or pivoting to internal networks. This could lead to data breaches, disruption of business operations, or compromise of sensitive information. Small and medium enterprises using Belkin F9K1015 devices as part of their network infrastructure are particularly vulnerable, as these devices often lack advanced security monitoring. The absence of vendor patches means organizations must rely on alternative mitigations to reduce exposure. Additionally, the public availability of exploits increases the likelihood of opportunistic attacks targeting European networks, especially in sectors with less mature cybersecurity defenses. The impact extends beyond confidentiality to integrity and availability, potentially causing widespread service outages or persistent backdoors.

Given the absence of an official patch, European organizations should implement the following specific mitigations: 1) Immediately isolate or replace affected Belkin F9K1015 devices with updated or alternative hardware that is not vulnerable. 2) If replacement is not immediately feasible, restrict access to the router's management interface by implementing network segmentation and firewall rules to block external and unnecessary internal access to the /goform/formSetLanguage endpoint. 3) Employ intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect and block exploit attempts targeting this vulnerability. 4) Monitor network traffic for anomalous requests to the vulnerable endpoint and unusual device behavior indicative of exploitation. 5) Enforce strict network access controls and limit administrative access to trusted personnel only. 6) Maintain up-to-date asset inventories to identify all affected devices and prioritize their remediation. 7) Engage with Belkin support channels for updates and consider vendor alternatives for future deployments to avoid unsupported devices. 8) Educate IT staff about this vulnerability and the risks of using unpatched network devices.