CVE-2025-11300 is a buffer overflow vulnerability identified in the Belkin F9K1015 router firmware version 1.00.10. The vulnerability arises from improper handling of the ateFunc argument within an unspecified function tied to the /goform/formWlanMP endpoint. Buffer overflow vulnerabilities occur when input data exceeds the allocated buffer size, potentially overwriting adjacent memory and allowing attackers to execute arbitrary code or cause denial of service. This particular flaw is remotely exploitable over the network without requiring authentication or user interaction, significantly increasing its risk profile. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). The exploit code has been publicly released, increasing the likelihood of active exploitation, although no confirmed in-the-wild attacks have been reported yet. The vendor, Belkin, was notified early but has not issued any response or patch, leaving affected devices vulnerable. The lack of patch availability means that affected organizations must rely on compensating controls to mitigate risk. The vulnerability could allow attackers to gain full control over the router, manipulate network traffic, intercept sensitive data, or disrupt network availability. Given the critical role routers play in network security and connectivity, exploitation could have cascading effects on enterprise networks and connected systems.

For European organizations, this vulnerability poses a significant risk, especially for those using Belkin F9K1015 routers in their network infrastructure. Successful exploitation could lead to unauthorized remote code execution, enabling attackers to take full control of the device. This compromises the confidentiality of network traffic, integrity of routing and firewall rules, and availability of network services. Critical sectors such as finance, healthcare, government, and telecommunications could face severe disruptions or data breaches. The lack of vendor response and patch availability increases the window of exposure, making these devices attractive targets for attackers. Additionally, the public availability of exploit code lowers the barrier for exploitation by less sophisticated threat actors. European organizations with remote management enabled on these routers are particularly vulnerable. The impact extends beyond individual organizations, as compromised routers can be leveraged for lateral movement, launching further attacks within corporate networks or as part of botnets targeting other entities.

1. Immediately identify and inventory all Belkin F9K1015 devices running firmware version 1.00.10 within the network. 2. Disable remote management interfaces and restrict access to router management to trusted internal IP addresses only. 3. Segment networks to isolate vulnerable routers from critical systems and sensitive data environments. 4. Implement strict firewall rules to block unauthorized access attempts to the /goform/formWlanMP endpoint or related services. 5. Monitor network traffic and logs for unusual activity or exploitation attempts targeting this vulnerability. 6. Employ intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect exploitation attempts. 7. Engage with Belkin support channels regularly to obtain any forthcoming patches or advisories. 8. Consider replacing affected devices with models from vendors with active security support if patching is not forthcoming. 9. Educate IT staff about this vulnerability and the importance of rapid response to emerging threats. 10. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.