CVE-2025-41749 is a cross-site scripting (XSS) vulnerability identified in the Phoenix Contact FL SWITCH 2005 device, specifically in the port_util.php component of its web-based management (WBM) interface. The vulnerability arises from improper neutralization of input during web page generation (CWE-79), allowing an attacker to inject malicious scripts into the web interface. An unauthenticated remote attacker can exploit this by crafting a malicious URL that, when clicked by an authenticated user, executes arbitrary script code within the user's browser context. This can lead to unauthorized changes to device configuration parameters accessible via the WBM. However, the vulnerability does not grant access to underlying operating system internals or privileged functions, limiting the scope to web application-level configuration changes. The session cookie is protected by the httpOnly flag, preventing session hijacking via script access. The CVSS 3.1 base score of 7.1 reflects a network attack vector with low attack complexity, no privileges required, but requiring user interaction, and impacting confidentiality, integrity, and availability with limited scope. The vulnerability was reserved in April 2025 and published in December 2025, with no known exploits in the wild as of now. The lack of patch links suggests that a fix may not yet be publicly available, emphasizing the need for interim mitigations. This vulnerability is particularly relevant for industrial control environments where FL SWITCH 2005 devices are deployed, as unauthorized configuration changes could disrupt network segmentation, traffic flow, or security controls.

For European organizations, especially those in industrial, manufacturing, energy, and critical infrastructure sectors that rely on Phoenix Contact FL SWITCH 2005 devices, this vulnerability poses a significant risk. Unauthorized modification of switch configuration parameters could lead to network disruptions, bypassing of security controls, or exposure of sensitive operational data. Although the vulnerability does not allow direct system compromise or session hijacking, the ability to alter device settings remotely via social engineering could facilitate further attacks or operational failures. Given the widespread use of Phoenix Contact products in European industrial automation and control systems, exploitation could impact operational continuity and safety. The requirement for user interaction (clicking a malicious link) means that phishing or targeted spear-phishing campaigns could be effective vectors. The vulnerability's high severity score underscores the potential for substantial impact on confidentiality, integrity, and availability of network infrastructure within European organizations.

1. Implement strict input validation and output encoding on the port_util.php component to neutralize malicious scripts, ideally by applying vendor patches once available. 2. Restrict access to the web-based management interface to trusted networks only, using network segmentation and firewall rules to limit exposure. 3. Employ multi-factor authentication (MFA) for accessing the WBM to reduce the risk of unauthorized access even if a user is tricked. 4. Conduct user awareness training focused on phishing and social engineering to reduce the likelihood of users clicking malicious links. 5. Monitor network traffic and device logs for unusual configuration changes or access patterns indicative of exploitation attempts. 6. If patching is not immediately possible, consider disabling or restricting the vulnerable web interface temporarily or using web application firewalls (WAF) to detect and block XSS payloads. 7. Regularly update and audit device firmware and management software to ensure all security updates are applied promptly. 8. Use browser security features and extensions that can help detect and block XSS attacks at the client side.