CVE-2025-4368 is a critical buffer overflow vulnerability identified in the Tenda AC8 router, specifically in firmware version 16.03.34.06. The flaw exists in the function formGetRouterStatus within the /goform/MtuSetMacWan endpoint. An attacker can manipulate the 'shareSpeed' argument to trigger a buffer overflow condition. This vulnerability is remotely exploitable without requiring user interaction or authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The vulnerability impacts confidentiality, integrity, and availability with high severity, as it can potentially allow remote code execution or denial of service. The vulnerability has been publicly disclosed, increasing the risk of exploitation, although no known exploits in the wild have been reported yet. The CVSS 4.0 score of 8.7 reflects the high impact and ease of exploitation. The absence of patches at the time of disclosure means affected users remain vulnerable. This vulnerability targets a widely used consumer and small office/home office (SOHO) router model, which is often deployed in environments with limited security monitoring, increasing the risk of compromise.

For European organizations, the impact of this vulnerability can be significant, especially for small and medium enterprises (SMEs) and home office users relying on the Tenda AC8 router for internet connectivity. Exploitation could lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network availability. This could facilitate lateral movement within corporate networks, data exfiltration, or deployment of malware. Given the router's role as a network gateway, compromise could undermine perimeter defenses and expose connected devices to further attacks. Critical infrastructure or organizations with remote workforces using vulnerable routers may face increased risk. The lack of authentication and user interaction requirements lowers the barrier for attackers, potentially enabling automated exploitation campaigns targeting European networks.

1. Immediate mitigation should focus on isolating the vulnerable Tenda AC8 devices from critical network segments to limit potential impact. 2. Network administrators should monitor traffic to and from the /goform/MtuSetMacWan endpoint for anomalous requests, particularly those manipulating the 'shareSpeed' parameter. 3. Deploy network-based intrusion detection/prevention systems (IDS/IPS) with custom signatures targeting this exploit pattern. 4. Encourage users to upgrade firmware once Tenda releases a patch; until then, consider replacing vulnerable devices with models from vendors with timely security updates. 5. Implement network segmentation to reduce exposure of vulnerable routers to untrusted networks. 6. Enforce strict access controls on router management interfaces, restricting remote access where possible. 7. Conduct regular vulnerability scans to identify presence of affected firmware versions within organizational networks. 8. Educate users about the risks of using outdated router firmware and the importance of applying security updates promptly.