CVE-2025-11297 identifies a buffer overflow vulnerability in the Belkin F9K1015 router firmware version 1.00.10. The vulnerability arises from improper handling of input parameters in the /goform/formSetLanguage endpoint, specifically the 'webpage' argument. When an attacker sends a specially crafted request manipulating this argument, it causes a buffer overflow condition. This can lead to memory corruption, enabling remote code execution or denial of service on the affected device. The attack vector is network-based, requiring no authentication or user interaction, making it highly accessible to remote attackers. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity due to its ease of exploitation and potential impact on confidentiality, integrity, and availability. The vendor, Belkin, has not responded to disclosure requests, and no patches are currently available. The exploit code has been publicly released, increasing the risk of exploitation. The affected device is commonly used as a consumer and small office/home office router, which may be deployed in various organizational environments. This vulnerability could be leveraged to gain unauthorized control over network traffic, intercept sensitive data, or disrupt network services. Given the lack of vendor mitigation, organizations must rely on network defenses and monitoring to reduce exposure.

For European organizations, exploitation of this vulnerability could result in unauthorized remote control of affected routers, leading to interception or manipulation of network traffic, disruption of internet connectivity, and potential lateral movement within internal networks. This is particularly critical for small and medium enterprises (SMEs) and home office setups that rely on Belkin F9K1015 devices without advanced security monitoring. Confidentiality could be compromised through data interception, integrity affected by traffic manipulation, and availability impaired by denial of service conditions. The public availability of exploit code increases the likelihood of attacks, potentially targeting critical infrastructure or sensitive business environments. The absence of vendor patches prolongs the window of exposure, necessitating immediate defensive measures. Additionally, compromised routers could be recruited into botnets or used as pivot points for broader attacks against European networks.

Given the lack of vendor patches, European organizations should implement the following specific mitigations: 1) Immediately isolate or replace Belkin F9K1015 devices running firmware 1.00.10 with updated or alternative hardware where possible. 2) Employ network segmentation to limit access to vulnerable routers, restricting management interfaces to trusted internal networks only. 3) Deploy intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection capable of identifying exploitation attempts targeting /goform/formSetLanguage or unusual HTTP requests. 4) Use firewall rules to block unsolicited inbound traffic to router management endpoints from untrusted sources. 5) Monitor network traffic for signs of exploitation, such as unexpected crashes or abnormal behavior of routers. 6) Educate users and administrators about the vulnerability and the risks of using unsupported firmware. 7) Engage with Belkin or authorized resellers to seek firmware updates or official guidance. 8) Consider implementing network access control (NAC) to prevent compromised devices from affecting critical network segments. These steps go beyond generic advice by focusing on device isolation, traffic filtering, and active monitoring tailored to this specific vulnerability.