CVE-2025-60335 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 main function when processing HTTP requests. This type of vulnerability (CWE-476) leads to a denial of service condition by causing the router's software to crash or hang, resulting in loss of network availability. The vulnerability can be triggered remotely by an unauthenticated attacker sending a specially crafted HTTP request to the device's management interface. The CVSS v3.1 base score of 7.5 reflects the high severity due to network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability (no confidentiality or integrity impact). No patches or firmware updates have been published yet, and no exploits are known in the wild. The vulnerability affects the specific firmware version mentioned, and the lack of authentication requirement makes it a critical concern for exposed devices. The vulnerability could be leveraged to disrupt network connectivity for organizations relying on these routers, potentially impacting business operations and critical services.

For European organizations, exploitation of CVE-2025-60335 could lead to denial of service on network edge devices, causing loss of internet connectivity or internal network segmentation failures. This can disrupt business operations, remote work, and access to cloud services. Critical infrastructure sectors such as healthcare, finance, and government agencies using TOTOLINK N600R routers may experience outages affecting service availability and operational continuity. The vulnerability's remote exploitability without authentication increases risk, especially for devices exposed to the internet or poorly segmented internal networks. While no data confidentiality or integrity is directly impacted, the availability loss can have cascading effects on dependent systems and services. Organizations with limited IT support or patch management capabilities may face prolonged downtime. The absence of known exploits currently provides a window for proactive mitigation, but the threat remains significant given the ease of triggering the DoS condition.

1. Immediately audit network environments to identify any TOTOLINK N600R routers running the vulnerable firmware version 4.3.0cu.7866_B20220506. 2. Restrict access to router management interfaces by implementing network segmentation and firewall rules to allow only trusted IP addresses. 3. Disable remote HTTP management access if not required, or replace it with more secure management protocols such as HTTPS or VPN-based access. 4. Monitor network traffic for unusual HTTP requests targeting router management interfaces that could indicate exploitation attempts. 5. Engage with TOTOLINK support channels to obtain information about upcoming patches or firmware updates addressing this vulnerability and apply them promptly once available. 6. Consider replacing vulnerable devices with alternative routers that receive timely security updates if patching is not feasible. 7. Implement network redundancy and failover mechanisms to minimize impact in case of device failure due to exploitation. 8. Educate IT staff about this vulnerability and ensure incident response plans include procedures for handling router DoS events.