CVE-2025-5907 is a critical buffer overflow vulnerability identified in the TOTOLINK EX1200T router firmware versions up to 4.1.2cu.5232_B20210713. The vulnerability exists in the HTTP POST request handler component, specifically within the /boafrm/formFilter endpoint. An attacker can remotely send specially crafted HTTP POST requests to this endpoint, causing a buffer overflow condition. This type of vulnerability can lead to arbitrary code execution, denial of service, or system compromise without requiring any user interaction or authentication. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity, with an attack vector of network (remote), low attack complexity, no privileges required, and no user interaction needed. The impact metrics indicate high confidentiality, integrity, and availability impacts, meaning successful exploitation could allow an attacker to fully control the device or disrupt its operation. Although no known exploits are currently reported in the wild, the public disclosure of the exploit code increases the risk of imminent attacks. The TOTOLINK EX1200T is a consumer and small office/home office (SOHO) router, which is widely deployed in various regions including Europe. The vulnerability affects the core network management interface, making it a critical risk for network infrastructure security.

For European organizations, this vulnerability poses a significant threat to network security, especially for small and medium enterprises (SMEs) and home office users relying on TOTOLINK EX1200T routers. Exploitation could lead to unauthorized remote control of the router, enabling attackers to intercept, modify, or redirect network traffic, potentially compromising sensitive corporate data and communications. The disruption or takeover of network devices can also facilitate lateral movement within corporate networks, increasing the risk of broader compromise. Additionally, compromised routers can be used as launch points for further attacks, including distributed denial-of-service (DDoS) attacks, which can affect service availability. Given the critical nature of this vulnerability and the lack of authentication or user interaction requirements, European organizations face an elevated risk, particularly if devices are exposed directly to the internet or poorly segmented from critical infrastructure.

To mitigate this vulnerability effectively, European organizations should: 1) Immediately identify and inventory all TOTOLINK EX1200T devices within their networks. 2) Apply the latest firmware updates from TOTOLINK as soon as they become available, as the current information does not list a patch but monitoring vendor advisories is essential. 3) If patches are not yet available, restrict access to the router’s management interface by implementing network segmentation and firewall rules to block inbound HTTP POST requests to the /boafrm/formFilter endpoint from untrusted networks. 4) Disable remote management features on the router if not required, or restrict remote management access to trusted IP addresses only. 5) Monitor network traffic and router logs for unusual activity indicative of exploitation attempts, such as unexpected HTTP POST requests or crashes. 6) Consider replacing vulnerable devices with models from vendors with stronger security track records if timely patching is not feasible. 7) Educate IT staff and users about the risks of exposed network devices and the importance of timely updates and secure configurations.