CVE-2025-7090 is a critical security vulnerability identified in the Belkin F9K1122 router, specifically version 1.00.33. The vulnerability exists in the web management interface component, within the function formConnectionSetting located at the endpoint /goform/formConnectionSetting. The issue arises from improper handling of the input parameters max_Conn and timeOut, which can be manipulated to trigger a stack-based buffer overflow. This type of overflow occurs when more data is written to a buffer located on the stack than it can hold, potentially overwriting adjacent memory and allowing an attacker to execute arbitrary code or cause a denial of service. The vulnerability is remotely exploitable without requiring user interaction or authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L), meaning an attacker with limited privileges on the network could exploit it. The CVSS score of 8.7 (high severity) reflects the significant impact on confidentiality, integrity, and availability, with high impact on all three (VC:H/VI:H/VA:H). Although the vendor was notified early, there has been no response or patch released, and a public exploit has been disclosed, increasing the risk of exploitation. The vulnerability affects the router’s web server component, which is critical for device configuration and management, making exploitation potentially devastating for network security and stability.

For European organizations, the impact of this vulnerability could be substantial. Belkin routers like the F9K1122 are commonly used in small to medium business environments and home offices, which are integral parts of corporate networks or remote work setups. Exploitation could allow attackers to gain control over the router, intercept or manipulate network traffic, disrupt internet connectivity, or pivot to internal networks, leading to data breaches, espionage, or operational disruption. Given the remote exploitability without user interaction, attackers could launch automated attacks at scale. The lack of vendor response and patch availability exacerbates the risk, potentially leaving many devices vulnerable for extended periods. This is particularly concerning for sectors with stringent data protection requirements under GDPR, such as finance, healthcare, and government entities, where compromised network infrastructure could lead to regulatory penalties and reputational damage.

Immediate mitigation steps include isolating affected Belkin F9K1122 routers from critical network segments and restricting access to their web management interfaces to trusted administrative networks only, preferably via VPN or secure management VLANs. Network administrators should monitor network traffic for unusual activity targeting the /goform/formConnectionSetting endpoint and implement intrusion detection/prevention systems (IDS/IPS) signatures to detect exploitation attempts. Where possible, replace vulnerable devices with alternative routers from vendors with active security support. If replacement is not immediately feasible, consider disabling remote management features or restricting management access to specific IP addresses. Regularly audit network devices for firmware versions and maintain an asset inventory to identify all affected units. Organizations should also prepare incident response plans for potential exploitation scenarios and monitor threat intelligence feeds for emerging exploits or patches.