CVE-2025-55852 is a high-severity buffer overflow vulnerability identified in the Tenda AC8 router firmware version 16.03.34.06. The vulnerability exists in the formWifiBasicSet function, specifically triggered via the parameters 'security' or 'security_5g'. Buffer overflow vulnerabilities occur when a program writes more data to a buffer than it can hold, potentially overwriting adjacent memory. In this case, the overflow can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability does not impact confidentiality or integrity directly but results in a high impact on availability (A:H), meaning an attacker can cause denial of service or potentially crash the device. The CWE classification CWE-121 confirms this is a classic stack-based buffer overflow. Although no known exploits are reported in the wild yet, the ease of exploitation and the network attack vector make this a significant threat. The lack of available patches at the time of publication increases the risk for affected users. The Tenda AC8 is a widely used consumer-grade wireless router, and exploitation could disrupt home or small office network connectivity, potentially impacting business operations relying on these devices.

For European organizations, the impact of this vulnerability could be substantial, especially for small and medium enterprises (SMEs) and home offices that rely on Tenda AC8 routers for internet connectivity. An attacker exploiting this vulnerability could cause network outages by crashing the router, leading to loss of availability of internet services. This disruption can affect business continuity, remote work capabilities, and access to cloud services. While the vulnerability does not directly compromise data confidentiality or integrity, the denial of service could indirectly affect security monitoring, incident response, and communications. Additionally, if attackers leverage the buffer overflow for further exploitation (e.g., remote code execution), the impact could escalate, though this is not confirmed. Given the router’s role as a network gateway, persistent denial of service could also expose organizations to secondary risks such as delayed security updates or inability to access security tools hosted externally.

Organizations and users should immediately assess their network environments for the presence of Tenda AC8 routers running firmware version 16.03.34.06. Since no patches are currently available, mitigation should focus on network-level protections: 1) Restrict remote access to router management interfaces by disabling WAN-side administration and limiting access to trusted IP addresses. 2) Implement network segmentation to isolate vulnerable devices from critical infrastructure. 3) Employ intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious traffic targeting the vulnerable parameters. 4) Regularly monitor vendor communications for firmware updates or patches and apply them promptly once released. 5) Consider temporary replacement or upgrade of affected devices with models from vendors with active security support. 6) Educate users about the risks of exposing router management interfaces and encourage strong administrative passwords and secure configurations. These steps go beyond generic advice by focusing on compensating controls until a patch is available.