CVE-2025-50611 is a high-severity buffer overflow vulnerability identified in the Netis WF2880 router firmware version 2.1.40207. The vulnerability exists in the FUN_00473154 function within the cgitest.cgi file, which is part of the router's web management interface. Specifically, the flaw can be triggered by an attacker who crafts a malicious payload controlling the values of the parameters wl_sec_set_5g and wl_sec_rp_set_5g. By manipulating these parameters, an attacker can cause a buffer overflow condition that leads to the program crashing, resulting in a Denial of Service (DoS) condition. The vulnerability does not require any authentication or user interaction and can be exploited remotely over the network, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). Although the vulnerability does not impact confidentiality or integrity directly, the availability of the affected device is compromised. The weakness is classified under CWE-120, which corresponds to classic buffer overflow issues that arise from improper bounds checking. No known exploits are currently reported in the wild, and no patches have been linked yet, which suggests that affected users should be vigilant and monitor for vendor updates. The vulnerability affects a specific Netis router model widely used in home and small office environments, which often have limited security monitoring and may be exposed to the internet or local network threats.

For European organizations, especially small and medium enterprises (SMEs) and home office users relying on Netis WF2880 routers, this vulnerability poses a significant risk to network availability. A successful exploitation could disrupt internet connectivity and internal network operations by crashing the router’s management interface, leading to downtime and potential loss of productivity. While the vulnerability does not allow data theft or modification, the denial of service could be leveraged as part of a larger attack chain, for example, to facilitate lateral movement or distract from other malicious activities. Critical infrastructure or organizations with remote workers using this router model may experience operational interruptions. Additionally, since the router is often used in less-secured environments, the risk of exploitation increases, especially if the device is exposed to the internet without proper firewall protections. The lack of authentication requirement means attackers can exploit this vulnerability without prior access, increasing the attack surface. The absence of a patch at the time of disclosure further elevates the risk until mitigations are applied.

European organizations should immediately audit their network environments to identify the presence of Netis WF2880 routers running firmware version 2.1.40207. Until an official patch is released, it is critical to restrict access to the router’s web management interface by implementing network segmentation and firewall rules that limit access to trusted IP addresses only. Disabling remote management features or changing default management ports can reduce exposure. Monitoring network traffic for unusual requests targeting the cgitest.cgi endpoint and the specific parameters (wl_sec_set_5g and wl_sec_rp_set_5g) can help detect attempted exploitation. Organizations should also consider replacing affected devices with models from vendors that provide timely security updates if patching is not forthcoming. Regularly checking the vendor’s website or trusted vulnerability databases for firmware updates addressing this issue is essential. Additionally, educating users about the risks of exposing router management interfaces to the internet and enforcing strong network perimeter defenses will mitigate exploitation risks.