CVE-2025-6165 is a critical buffer overflow vulnerability identified in the TOTOLINK X15 router, specifically version 1.0.0-B20230714.1105. The flaw exists within the HTTP POST request handler component, targeting the /boafrm/formTmultiAP endpoint. The vulnerability arises from improper handling of the 'submit-url' argument, which can be manipulated by an attacker to trigger a buffer overflow condition. This type of vulnerability allows an attacker to overwrite memory adjacent to the buffer, potentially leading to arbitrary code execution, denial of service, or system compromise. The attack vector is remote and requires no user interaction or authentication, making exploitation straightforward. The CVSS 4.0 base score is 8.7 (high severity), reflecting the ease of exploitation (network attack vector, low complexity), no privileges required, and no user interaction needed. The impact on confidentiality, integrity, and availability is high, as successful exploitation could allow attackers to execute arbitrary code with elevated privileges, disrupt router functionality, or intercept network traffic. Although no public exploits are currently confirmed in the wild, the vulnerability details have been disclosed, increasing the risk of exploitation. The TOTOLINK X15 is a consumer and small office/home office (SOHO) router, and such devices are often deployed in residential and small business environments, which may lack robust security monitoring. The vulnerability's presence in a widely used router model raises concerns about potential widespread impact if exploited at scale.

For European organizations, especially small and medium enterprises (SMEs) and residential users relying on TOTOLINK X15 routers, this vulnerability poses a significant risk. Exploitation could lead to unauthorized network access, interception of sensitive data, or disruption of internet connectivity. In business environments, compromised routers can serve as footholds for lateral movement into internal networks, potentially exposing corporate resources and intellectual property. The high severity and remote exploitability increase the urgency for mitigation. Critical infrastructure operators using these devices in edge or branch locations could face operational disruptions. Additionally, the vulnerability could be leveraged in botnet campaigns or as part of multi-stage attacks targeting European networks. The lack of authentication and user interaction requirements means attackers can scan and exploit vulnerable devices en masse, increasing the potential scale of impact across Europe.

Immediately identify and inventory all TOTOLINK X15 routers running version 1.0.0-B20230714.1105 within the organization’s network. Apply firmware updates from TOTOLINK as soon as they become available. In the absence of an official patch, consider temporary mitigations such as disabling remote management features or restricting access to the router’s management interface via firewall rules to trusted IP addresses only. Implement network segmentation to isolate vulnerable routers from critical internal systems, minimizing potential lateral movement if compromised. Deploy intrusion detection/prevention systems (IDS/IPS) configured to detect anomalous HTTP POST requests targeting /boafrm/formTmultiAP or unusual traffic patterns indicative of exploitation attempts. Conduct regular vulnerability scans and penetration tests focusing on network edge devices to identify unpatched or misconfigured routers. Educate users and IT staff about the risks associated with outdated router firmware and the importance of timely updates. Consider replacing vulnerable TOTOLINK X15 devices with models from vendors with stronger security track records if patching is delayed or unavailable. Monitor threat intelligence feeds for emerging exploit code or active campaigns targeting this vulnerability to adjust defensive measures accordingly.