CVE-2025-11549 is a stack-based buffer overflow vulnerability identified in the Tenda W12 router firmware version 3.0.0.6(3948). The vulnerability resides in the wifiMacFilterSet function located in the /goform/modules directory, which is part of the HTTP Request Handler component. Specifically, the vulnerability arises from improper validation and handling of the 'mac' argument passed to this function, allowing an attacker to craft a specially malformed HTTP request that causes a stack buffer overflow. This overflow can overwrite the stack memory, potentially enabling remote code execution or denial of service. The attack vector is network-based (AV:N), requiring no user interaction (UI:N) and no authentication (AT:N), making it highly accessible to remote attackers. The CVSS 4.0 base score is 8.7, reflecting high impact on confidentiality, integrity, and availability due to the potential for full device compromise. The vulnerability has been publicly disclosed, though no known exploits have been observed in the wild yet. The lack of available patches at the time of disclosure increases the urgency for mitigation. This vulnerability could be exploited to gain control over the router, intercept or manipulate network traffic, or disrupt network services.

The impact of CVE-2025-11549 is significant for organizations using Tenda W12 routers, as successful exploitation can lead to complete compromise of the device. Attackers can execute arbitrary code remotely, potentially gaining persistent access to internal networks. This can result in interception of sensitive data, network traffic manipulation, or launching further attacks within the network. The availability of network services may be disrupted, causing operational downtime. Given that routers are critical infrastructure components, this vulnerability could affect enterprise networks, ISPs, and home users alike. The ease of exploitation without authentication or user interaction increases the risk of widespread attacks. Organizations may face data breaches, loss of network integrity, and reputational damage if exploited. The absence of patches at disclosure time further exacerbates the threat, requiring immediate mitigation to prevent exploitation.

1. Immediate mitigation should include isolating affected Tenda W12 devices from untrusted networks to reduce exposure. 2. Monitor network traffic for unusual HTTP requests targeting the /goform/modules endpoint, especially those containing malformed 'mac' parameters. 3. Implement network-level filtering or intrusion prevention system (IPS) rules to detect and block exploit attempts targeting this vulnerability. 4. Contact Tenda support or check official channels frequently for firmware updates or patches addressing CVE-2025-11549 and apply them promptly once available. 5. As a temporary workaround, disable remote management interfaces on the router to limit attack surface. 6. Conduct regular security audits of network devices to identify vulnerable firmware versions. 7. Employ network segmentation to limit the impact of compromised devices. 8. Educate network administrators about this vulnerability and ensure incident response plans include steps for router compromise scenarios.