CVE-2025-57570 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 QosList parameter in the goform/setQoS endpoint. Specifically, the buffer overflow occurs when the input data for the QosList parameter exceeds the expected bounds, leading to memory corruption. This type of vulnerability can potentially allow an attacker to execute arbitrary code on the device, cause a denial of service by crashing the router, or manipulate the router's QoS settings maliciously. The goform/setQoS endpoint is likely part of the router's web management interface, which may be accessible locally or remotely depending on the device configuration. Exploitation would typically require sending a specially crafted HTTP request to this endpoint. Although no known exploits are currently reported in the wild, the nature of buffer overflow vulnerabilities makes this a significant risk, especially if the router's management interface is exposed to untrusted networks. The lack of a CVSS score and patch information suggests this is a newly disclosed vulnerability, and users may not yet have an official fix available. Given the widespread use of Tenda routers in consumer and small business environments, this vulnerability could be leveraged to compromise network infrastructure or pivot into internal networks.

For European organizations, the impact of this vulnerability can be substantial, particularly for small and medium enterprises (SMEs) and home office setups that rely on Tenda F3 routers for internet connectivity and network management. Successful exploitation could lead to unauthorized control over the router, enabling attackers to intercept, modify, or redirect network traffic, degrade network performance, or launch further attacks against internal systems. Confidentiality could be compromised through traffic interception, integrity could be affected by tampering with QoS settings or routing rules, and availability could be disrupted by causing router crashes or network outages. The risk is heightened if the router's management interface is accessible from the internet or if default credentials are used. Additionally, compromised routers could be enlisted into botnets or used as a foothold for lateral movement within corporate networks. Given the critical role of network devices in maintaining operational continuity, this vulnerability poses a direct threat to business operations and data security in European contexts.

To mitigate this vulnerability, European organizations should first identify all Tenda F3 routers in their environment and verify the firmware version. Until an official patch is released, it is advisable to restrict access to the router's management interface by disabling remote management or limiting it to trusted IP addresses. Network segmentation should be employed to isolate routers from critical systems. Implement strong, unique passwords for router administration to prevent unauthorized access. Monitoring network traffic for unusual patterns or unexpected QoS configuration changes can help detect exploitation attempts. If possible, replace vulnerable devices with models from vendors with timely security updates. Organizations should also subscribe to vendor advisories and CVE databases to promptly apply patches once available. Employing intrusion detection systems (IDS) that can detect anomalous HTTP requests targeting the goform/setQoS endpoint may provide early warning of exploitation attempts. Finally, educating users about the risks of exposing router management interfaces and enforcing strict network access controls will reduce the attack surface.