CVE-2025-11549 is a stack-based buffer overflow vulnerability identified in the Tenda W12 router firmware version 3.0.0.6(3948). The flaw resides in the wifiMacFilterSet function located in the /goform/modules path of the HTTP Request Handler component. Specifically, the vulnerability arises from improper validation and handling of the mac argument passed to this function, which allows an attacker to overwrite the stack memory. This type of vulnerability can lead to arbitrary code execution, denial of service, or complete device compromise. The vulnerability is remotely exploitable without requiring authentication or user interaction, making it highly dangerous. The CVSS 4.0 base score is 8.7, reflecting high severity due to network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Although no confirmed exploits have been observed in the wild, the public disclosure of exploit details increases the likelihood of exploitation attempts. The affected product, Tenda W12, is a consumer and small office/home office (SOHO) Wi-Fi 6 router, commonly used for wireless networking. The vulnerability could be leveraged by attackers to gain unauthorized control over the router, intercept or manipulate network traffic, or disrupt network services.

For European organizations, the exploitation of CVE-2025-11549 could lead to severe consequences including unauthorized access to internal networks, interception of sensitive data, disruption of business operations, and potential lateral movement within corporate environments. Organizations relying on Tenda W12 routers for critical connectivity may experience network outages or compromised data integrity. The vulnerability’s remote exploitability without authentication significantly raises the risk profile, especially for organizations with exposed management interfaces or insufficient network segmentation. Given the router’s role as a network gateway, successful exploitation could undermine perimeter defenses and facilitate further attacks such as malware deployment or espionage. Small and medium enterprises, as well as home office setups prevalent in Europe, may be particularly vulnerable due to limited IT security resources and delayed patching cycles.

1. Immediately monitor for firmware updates or security patches released by Tenda addressing CVE-2025-11549 and apply them promptly. 2. Until patches are available, disable remote management interfaces on Tenda W12 devices to prevent external exploitation. 3. Restrict network access to router management ports using firewall rules or network segmentation to limit exposure. 4. Implement network intrusion detection/prevention systems (IDS/IPS) to identify and block suspicious HTTP requests targeting the wifiMacFilterSet function. 5. Conduct regular network traffic analysis to detect anomalous activities indicative of exploitation attempts. 6. Educate users and administrators about the risks of using outdated router firmware and enforce strict patch management policies. 7. Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed or unsupported.