CVE-2025-41747 is a cross-site scripting (XSS) vulnerability classified under CWE-79, affecting the Phoenix Contact FL SWITCH 2005 device's web-based management interface, specifically the pxc_vlanIntfCfg.php component. The vulnerability arises from improper neutralization of input during web page generation, allowing an unauthenticated remote attacker to craft a manipulated POST request that, when submitted by an authenticated user, can alter device configuration parameters accessible through the web interface. The attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), and the scope is changed (S:C) as it affects configuration integrity and availability. The impact includes limited confidentiality loss, integrity compromise, and availability degradation within the web application context, but does not extend to operating system or privileged system functions. The session cookie is protected with the httpOnly flag, mitigating session hijacking risks. The vulnerability was reserved in April 2025 and published in December 2025, with no known exploits or patches available at this time. This vulnerability could be leveraged in targeted attacks to disrupt or manipulate network switch configurations, potentially impacting network stability and security posture.

For European organizations, the impact of CVE-2025-41747 can be significant, especially for those relying on Phoenix Contact FL SWITCH 2005 devices in critical infrastructure, industrial control systems, or enterprise networks. Successful exploitation could lead to unauthorized changes in VLAN configurations or other network parameters, potentially causing network segmentation issues, unauthorized network access, or denial of service conditions. Although the vulnerability does not allow full system compromise or session hijacking, the ability to alter device configurations can undermine network security policies and operational stability. This risk is heightened in sectors such as manufacturing, energy, transportation, and utilities, where Phoenix Contact products are commonly deployed. The requirement for user interaction means social engineering or phishing tactics could be used to facilitate exploitation, increasing the threat vector. The absence of patches necessitates immediate compensating controls to mitigate risk.

1. Restrict access to the web-based management interface of FL SWITCH 2005 devices to trusted networks and users only, using network segmentation and access control lists (ACLs). 2. Implement strict input validation and sanitization on all user inputs at the application level, if possible via vendor updates or configuration. 3. Educate and train users to recognize and avoid phishing or social engineering attempts that could trick them into submitting malicious POST requests. 4. Monitor network traffic for unusual POST requests targeting pxc_vlanIntfCfg.php or other management endpoints. 5. Employ Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) with custom rules to detect and block XSS attack patterns against the device. 6. Regularly audit device configurations and logs for unauthorized changes. 7. Engage with Phoenix Contact for timely patch releases or firmware updates addressing this vulnerability. 8. Consider deploying multi-factor authentication (MFA) for web management interfaces to reduce risk from compromised credentials. 9. If possible, disable web management interfaces when not in use or replace with more secure management methods such as SSH with strong authentication.