The CVE-2025-63468 vulnerability affects the Totolink LR350 router, specifically firmware version 9.3.5u.6369_B20220309. The root cause is a stack overflow triggered by improper handling of the http_host parameter in the sub_426EF8 function. When an attacker sends a specially crafted HTTP request containing a malicious http_host value, the router’s software fails to properly validate or limit the input size, leading to a stack overflow condition. This overflow can cause the router’s process to crash or become unresponsive, resulting in a Denial of Service (DoS) that disrupts network connectivity for users relying on the device. The vulnerability does not require authentication, meaning an attacker can exploit it remotely without credentials, simply by sending a malicious HTTP request to the router’s management interface or exposed web services. No public exploits have been reported yet, and no official patches or firmware updates have been released at the time of this report. The lack of a CVSS score indicates this is a newly identified issue. The vulnerability’s impact is limited to DoS; there is no indication of code execution or data leakage. However, the disruption of network services can have significant operational consequences, especially in environments where these routers serve as critical network gateways. The vulnerability highlights the importance of input validation and secure coding practices in embedded device firmware.

For European organizations, the primary impact of CVE-2025-63468 is the potential for network outages caused by Denial of Service attacks targeting Totolink LR350 routers. This can disrupt business operations, especially for small and medium enterprises or branch offices that rely on these routers for internet connectivity. Critical infrastructure sectors such as healthcare, manufacturing, and finance could experience service degradation or loss of connectivity, affecting productivity and potentially leading to financial losses. The vulnerability’s remote exploitability without authentication increases the risk of opportunistic attacks from external threat actors. Additionally, organizations with limited network segmentation or exposed management interfaces are more vulnerable. Although no data breach or remote code execution is involved, the availability impact alone can be significant in environments requiring high uptime. The absence of a patch means organizations must rely on network-level mitigations until firmware updates are available. This vulnerability also raises concerns about the security posture of embedded network devices widely deployed in European networks.

To mitigate CVE-2025-63468, European organizations should immediately restrict access to the Totolink LR350 router’s management interface by implementing network segmentation and firewall rules that limit HTTP access to trusted IP addresses only. Disable remote management over HTTP or move management interfaces to secure, isolated networks. Monitor network traffic for unusual or malformed HTTP requests targeting the http_host parameter and set up alerts for potential exploitation attempts. Employ intrusion detection/prevention systems (IDS/IPS) with signatures tuned to detect stack overflow attempts or anomalous HTTP requests. Regularly audit and inventory network devices to identify all Totolink LR350 routers and verify firmware versions. Engage with the vendor for timely firmware updates and apply patches as soon as they become available. Consider temporary replacement of vulnerable devices in critical environments if patching is delayed. Educate network administrators about this vulnerability and the importance of secure configuration and monitoring. Finally, maintain robust incident response plans to quickly address any DoS incidents caused by exploitation attempts.