CVE-2025-51569 is a cross-site scripting (XSS) vulnerability identified in the LB-Link BL-CPE300M router, specifically affecting its web interface. The vulnerability resides in the /goform/goform_get_cmd_process endpoint, where the 'cmd' parameter is not properly sanitized before being reflected in the HTTP response. This improper input validation allows an unauthenticated attacker to inject arbitrary JavaScript code that executes within the security context of the router's web interface origin. Exploitation requires user interaction, meaning the victim must access a crafted URL containing the malicious payload. Once executed, the injected script can perform actions such as stealing session cookies, manipulating the router's web interface, or conducting further attacks on devices within the local network. The vulnerability does not require authentication, increasing its risk profile, but the lack of a known exploit in the wild and absence of a CVSS score suggest it is newly disclosed. The affected device is a consumer or small office router model, and no specific firmware versions are detailed beyond the identifier 01.01.02P42U14_06. The lack of patch information indicates that a fix may not yet be available or publicly announced.

For European organizations, especially small and medium enterprises (SMEs) and home office users relying on the LB-Link BL-CPE300M router, this vulnerability poses a risk of unauthorized access and control over the router's web interface. Successful exploitation could lead to session hijacking, unauthorized configuration changes, or pivoting attacks into internal networks. This can compromise confidentiality by exposing sensitive network configurations and potentially intercepting or redirecting traffic. Integrity may be affected if attackers alter router settings or inject malicious scripts into network traffic. Availability impact is limited but could occur if attackers disrupt router functionality. Since exploitation requires user interaction, phishing or social engineering campaigns could be used to lure users into clicking malicious links. The threat is more significant in environments where this router model is prevalent and where users have limited technical expertise to recognize suspicious URLs or behavior. Additionally, compromised routers can serve as footholds for broader attacks against organizational networks or as part of botnets, increasing the overall threat landscape.

Organizations and users should first verify if their LB-Link BL-CPE300M routers are affected by checking the firmware version and vendor advisories. Until a patch is released, users should restrict access to the router's web interface by limiting it to trusted internal networks and disabling remote management features if enabled. Employ network segmentation to isolate IoT and networking devices from critical systems. Educate users about the risks of clicking unknown or suspicious links, especially those purporting to be related to router management. Implement web filtering solutions to block access to known malicious URLs. Monitor router logs for unusual access patterns or configuration changes. Where possible, replace vulnerable routers with models from vendors that provide timely security updates. Finally, maintain regular backups of router configurations to enable quick recovery if compromised.