CVE-2025-41751 is a cross-site scripting (CWE-79) vulnerability identified in the Phoenix Contact FL SWITCH 2005 device, specifically in the pxc_portCntr.php web management component. The vulnerability arises from improper neutralization of input during web page generation, allowing an attacker to inject malicious scripts. An unauthenticated remote attacker can exploit this by crafting a malicious URL that, when visited by an authenticated user, executes script code within the user's browser context. This enables the attacker to manipulate device configuration parameters accessible through the web-based management interface. However, the vulnerability does not grant access to underlying operating system functions or privileged system resources. The session cookie is protected by the httpOnly flag, preventing session hijacking via script access. The CVSS v3.1 score is 7.1 (high), reflecting network attack vector, low attack complexity, no privileges required, but requiring user interaction. The scope is changed, as the vulnerability affects the web application and potentially the device configuration state. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability highlights the risk of insufficient input validation in industrial network devices, which can lead to unauthorized configuration changes and potential disruption of network operations.

For European organizations, particularly those operating industrial control systems, manufacturing plants, or critical infrastructure networks, this vulnerability poses a significant risk. Exploitation could lead to unauthorized changes in switch configurations, potentially disrupting network traffic, causing denial of service, or creating backdoors for further attacks. Although the vulnerability does not allow full system compromise or session hijacking, the integrity and availability of network devices can be compromised, affecting operational continuity. Given the widespread use of Phoenix Contact products in European industrial sectors, the impact could extend to energy, transportation, and manufacturing industries. The requirement for user interaction limits mass exploitation but targeted spear-phishing or social engineering campaigns could be effective. The inability to escalate privileges or access OS-level functions reduces the risk of deeper system compromise but does not eliminate operational risks. Overall, the vulnerability could facilitate lateral movement or persistent misconfigurations within critical network infrastructure.

Organizations should immediately restrict access to the FL SWITCH 2005 web management interface to trusted networks and users, ideally via VPN or secure management VLANs. User awareness training should emphasize the risks of clicking unsolicited links, especially those purporting to be related to device management. Network segmentation can limit the exposure of vulnerable devices. Monitoring and logging of configuration changes should be enhanced to detect unauthorized modifications promptly. Since no patch is currently available, consider deploying web application firewalls (WAFs) or reverse proxies with input filtering to block malicious payloads targeting the vulnerable parameter. Once Phoenix Contact releases a security update, prioritize patching affected devices. Additionally, review and harden device configurations to minimize the attack surface, disable unnecessary web management features, and enforce strong authentication mechanisms. Incident response plans should include procedures for rapid containment and recovery from configuration tampering.