CVE-2025-8245 is a critical buffer overflow vulnerability identified in the TOTOLINK X15 router, specifically version 1.0.0-B20230714.1105. The flaw exists in the HTTP POST request handler component, within the /boafrm/formMultiAPVLAN endpoint. The vulnerability arises from improper handling of the 'submit-url' argument, which can be manipulated by an attacker to overflow a buffer. This overflow can lead to arbitrary code execution or cause the device to crash, impacting availability. The vulnerability is remotely exploitable without requiring user interaction or prior authentication, making it highly dangerous. The CVSS 4.0 score of 8.7 reflects the high severity, with attack vector being network-based, low attack complexity, no privileges or user interaction needed, and high impact on confidentiality, integrity, and availability. Although no public exploit is currently known to be actively used in the wild, the exploit code has been disclosed publicly, increasing the risk of imminent exploitation. The vulnerability affects a specific firmware version of the TOTOLINK X15 router, a device commonly used in home and small office networks for wireless connectivity. The lack of available patches at the time of publication further elevates the risk for affected users.

For European organizations, the impact of this vulnerability can be significant, especially for small and medium enterprises (SMEs) and home office setups that rely on TOTOLINK X15 routers for network connectivity. Successful exploitation could allow attackers to execute arbitrary code remotely, potentially gaining control over the router. This could lead to interception or manipulation of network traffic, disruption of internet access, and use of the compromised device as a foothold for further attacks within the internal network. Confidentiality of sensitive data transmitted through the network could be compromised, and integrity of communications could be undermined. The availability of network services could also be disrupted by crashes or denial-of-service conditions caused by the buffer overflow. Given the critical nature of the vulnerability and the ease of exploitation, organizations that have not updated or replaced vulnerable devices face a heightened risk of cyberattacks, including espionage, data theft, or ransomware campaigns leveraging compromised network infrastructure.

1. Immediate identification and inventory of all TOTOLINK X15 devices running the vulnerable firmware version (1.0.0-B20230714.1105) within the organization’s network. 2. Check for firmware updates or security patches from TOTOLINK; if available, apply them promptly. If no official patch exists, 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. 3. Segment networks to isolate vulnerable devices from critical infrastructure and sensitive data to limit potential lateral movement in case of compromise. 4. Monitor network traffic for unusual activity originating from or targeting TOTOLINK X15 devices, including unexpected outbound connections or attempts to exploit the /boafrm/formMultiAPVLAN endpoint. 5. Educate users about the risks of using outdated firmware and encourage regular updates of network devices. 6. Plan for device replacement if patches are unavailable or if devices are no longer supported by the vendor. 7. Implement network intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting this vulnerability.