CVE-2025-60336 is a vulnerability identified in the TOTOLINK N600R router firmware version 4.3.0cu.7866_B20220506. The root cause is a NULL pointer dereference occurring in the sub_41773C function when processing specially crafted HTTP requests. This vulnerability allows an unauthenticated remote attacker to trigger a Denial of Service (DoS) condition by sending malicious HTTP traffic to the affected device. The NULL pointer dereference leads to a crash or reboot of the router, resulting in temporary loss of network availability for all devices relying on the router for connectivity. The vulnerability does not require authentication or user interaction, increasing its risk profile. No CVSS score has been assigned yet, and no patches or official fixes have been released as of the publication date. There are no known exploits actively circulating in the wild, but the simplicity of the attack vector suggests potential for future exploitation. The affected product, TOTOLINK N600R, is a consumer-grade wireless router commonly used in small office and home office environments. The impact is primarily on availability, with no indication of confidentiality or integrity compromise. The vulnerability highlights the importance of robust input validation and error handling in embedded device firmware, particularly for network-facing services such as HTTP management interfaces.

For European organizations, the primary impact of CVE-2025-60336 is the potential disruption of network services due to router crashes or reboots caused by the crafted HTTP requests. This can lead to temporary loss of internet connectivity, affecting business operations, communications, and access to cloud services. Small and medium-sized enterprises (SMEs) and home offices that rely on TOTOLINK N600R routers are particularly vulnerable, as these devices often serve as the primary network gateway without redundant failover. In critical environments, such as remote work setups or small branch offices, this DoS could interrupt productivity and delay critical tasks. While the vulnerability does not appear to allow data theft or device takeover, the availability impact can indirectly affect confidentiality and integrity by disrupting security monitoring and patch management processes. The lack of patches and known exploits means organizations should proactively mitigate exposure to reduce risk. Additionally, the vulnerability could be leveraged as part of a larger attack chain or to cause disruption during geopolitical tensions or cyber campaigns targeting European infrastructure.

1. Immediately restrict access to the router's HTTP management interface by limiting it to trusted internal networks or VPN connections, preventing exposure to untrusted external sources. 2. Monitor TOTOLINK's official channels for firmware updates addressing this vulnerability and apply patches promptly once available. 3. Implement network segmentation to isolate critical systems from devices using vulnerable routers, minimizing potential impact. 4. Employ intrusion detection or prevention systems (IDS/IPS) to detect and block suspicious HTTP requests that could exploit this vulnerability. 5. Regularly audit and update router configurations to disable unnecessary services and reduce the attack surface. 6. For organizations with multiple affected devices, consider temporary replacement with alternative hardware until a patch is released. 7. Educate IT staff and users about the risks of exposing management interfaces and encourage best practices for device security. 8. Maintain robust network monitoring to quickly identify and respond to unusual device behavior indicative of exploitation attempts.