CVE-2025-57571 is a buffer overflow vulnerability identified in the Tenda F3 router firmware version V12.01.01.48_multi and later. The vulnerability arises from improper handling of the macFilterList parameter in the goform/setNAT endpoint. Buffer overflow vulnerabilities occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory. In this case, an attacker can craft a specially designed request targeting the macFilterList parameter to overflow the buffer, which may lead to arbitrary code execution, denial of service, or system instability. Since the vulnerability is located in the NAT configuration interface, which is typically accessible via the router's web management interface, exploitation may require network access to the device's administrative interface. However, if the interface is exposed to untrusted networks or if an attacker gains access to the internal network, exploitation becomes feasible. No CVSS score has been assigned yet, and there are no known exploits in the wild at the time of publication. The lack of patch links suggests that a fix may not yet be available, increasing the urgency for affected users to monitor for updates. The vulnerability affects a widely deployed consumer-grade router model, which is commonly used in home and small office environments. Given the critical role of routers in network traffic management and security, exploitation could allow attackers to intercept, manipulate, or disrupt network communications, potentially compromising connected devices and data confidentiality.

For European organizations, particularly small and medium enterprises (SMEs) and home offices relying on Tenda F3 routers, this vulnerability poses a significant risk. Successful exploitation could allow attackers to execute arbitrary code on the router, leading to full compromise of the device. This could enable attackers to intercept sensitive communications, redirect traffic to malicious sites, or create persistent backdoors within the network. The impact extends to confidentiality, integrity, and availability of network services. Given the router's role as a gateway device, compromise could facilitate lateral movement within organizational networks, potentially exposing internal systems and data. Additionally, disruption of NAT services could lead to denial of service, affecting business continuity. The absence of known exploits currently limits immediate widespread impact, but the vulnerability's nature makes it a likely target for future exploitation, especially if patches are delayed. European organizations with limited IT security resources may be particularly vulnerable due to challenges in timely firmware updates and network segmentation.

Organizations and users should immediately verify if their network infrastructure includes Tenda F3 routers running firmware version V12.01.01.48_multi or later. Until an official patch is released, it is critical to restrict access to the router's administrative interface by implementing network segmentation and firewall rules to limit management access to trusted hosts only. Disabling remote management features and changing default credentials can reduce exposure. Monitoring network traffic for unusual activity related to NAT configuration requests may help detect attempted exploitation. Users should subscribe to vendor security advisories to receive timely updates on patches or mitigations. Where feasible, consider replacing vulnerable devices with models from vendors with stronger security track records. Additionally, implementing network intrusion detection systems (NIDS) that can identify anomalous traffic patterns targeting router management interfaces can provide early warning. Regular backups of router configurations and network documentation will facilitate recovery if compromise occurs.