CVE-2025-9379 is a high-severity vulnerability identified in the Belkin AX1800 router, specifically in firmware version 1.1.00.016. The flaw resides within the Firmware Update Handler component, which is responsible for managing firmware updates on the device. The vulnerability is characterized by insufficient verification of data authenticity during the firmware update process. This means that the device does not adequately validate the integrity and authenticity of the firmware data it receives before applying updates. An attacker can exploit this remotely without requiring user interaction or prior authentication, leveraging the network accessibility of the device to inject malicious firmware or manipulate the update process. The CVSS 4.0 score of 8.6 reflects the critical nature of this flaw, highlighting its network attack vector, low attack complexity, and the absence of required authentication or user interaction. The impact metrics indicate high confidentiality, integrity, and availability impacts, meaning a successful exploit could lead to full compromise of the device, including unauthorized access, persistent control, and potential disruption of network services. The vendor, Belkin, was contacted early but has not responded or issued a patch, increasing the risk exposure. Although no known exploits are currently reported in the wild, the vulnerability’s characteristics make it a prime candidate for future exploitation by threat actors targeting home and small office networks that use this router model.

For European organizations, the impact of this vulnerability can be significant, especially for small and medium enterprises (SMEs) and home offices that rely on Belkin AX1800 routers for network connectivity. Exploitation could allow attackers to install malicious firmware, enabling persistent backdoors, interception of sensitive communications, or lateral movement within the network. This could lead to data breaches, espionage, or disruption of business operations. Given the router’s role as a network gateway, compromise could also facilitate attacks against connected devices, including IoT endpoints and internal servers. The lack of vendor response and patch availability prolongs the window of exposure, increasing the risk of targeted attacks. Additionally, the vulnerability could be leveraged in botnet campaigns or as part of supply chain attacks affecting European supply chains. Organizations with remote workers using this device are particularly vulnerable, as the attack vector is remote and does not require user interaction.

1. Immediate mitigation should involve network segmentation to isolate Belkin AX1800 devices from critical infrastructure and sensitive data systems, limiting potential lateral movement. 2. Implement strict firewall rules to restrict inbound and outbound traffic to and from the router, especially blocking unauthorized remote management ports and protocols. 3. Monitor network traffic for unusual firmware update attempts or unexpected communications originating from the router. 4. Where possible, replace affected Belkin AX1800 routers with alternative models or vendors that have confirmed patched firmware or are not vulnerable. 5. For organizations that must continue using the device, deploy compensating controls such as VPNs with strong encryption and multi-factor authentication to protect network access beyond the router. 6. Maintain heightened security awareness and incident response readiness to detect and respond to potential exploitation attempts. 7. Engage with Belkin support channels persistently to seek firmware updates or official guidance, and monitor vulnerability databases for any emerging patches or exploit disclosures.