CVE-2025-41713 is a medium-severity vulnerability affecting the WAGO CC100 0751-9301 industrial communication device. The root cause is an insecure default initialization of the device's switching resource during the boot process, classified under CWE-1188 (Insecure Default Initialization of Resource). Specifically, during a brief window after power-on but before the device completes its CPU-induced reset and proper configuration, the switch operates in an undefined state. In this state, an unauthenticated remote attacker can send network traffic to unauthorized networks that would normally be restricted. This behavior arises because the device's internal switching logic has not yet enforced its intended access controls or segmentation policies. The vulnerability does not require any user interaction or privileges, and the attacker can exploit it remotely over the network. The CVSS v3.1 base score is 6.5, reflecting a network attack vector with low complexity, no privileges required, no user interaction, and limited confidentiality impact but some availability impact due to potential unauthorized traffic flow. No known exploits are currently reported in the wild, and no patches have been published yet. The affected version is listed as '0', which likely refers to the initial or current firmware version at the time of disclosure. This vulnerability is particularly relevant for industrial control systems and critical infrastructure environments where WAGO devices are deployed, as unauthorized network traffic could lead to information leakage or disruption of operational processes during device startup.

For European organizations, especially those in industrial automation, manufacturing, energy, and critical infrastructure sectors, this vulnerability poses a risk during device boot cycles. Unauthorized network traffic could bypass segmentation controls temporarily, potentially allowing attackers to access sensitive networks or systems that are normally isolated. Although the window of exploitation is short, it could be leveraged in coordinated attacks targeting startup sequences or during maintenance windows. This could lead to limited confidentiality breaches or availability issues if malicious traffic disrupts network operations. Given the widespread use of WAGO devices in European industrial environments, the vulnerability could affect operational technology (OT) networks, increasing the risk of industrial espionage, sabotage, or disruption of essential services. The lack of authentication and user interaction requirements lowers the barrier for exploitation, making it a concern for organizations relying on these devices for secure network segmentation.

1. Implement network-level controls such as ingress and egress filtering on switches and routers to restrict unauthorized traffic flows, especially from devices known to be vulnerable during boot. 2. Use network segmentation and VLANs to isolate WAGO devices and limit the impact of any unauthorized traffic during startup. 3. Monitor device boot times and network traffic for anomalous patterns indicative of exploitation attempts during the vulnerable window. 4. Coordinate with WAGO for firmware updates or patches; if unavailable, consider deploying devices with updated firmware or alternative models with secure initialization. 5. Employ physical or logical access controls to restrict network access to critical devices during maintenance or reboot periods. 6. Where possible, schedule device reboots during low-risk periods and ensure that network monitoring is heightened during these times. 7. Use intrusion detection/prevention systems (IDS/IPS) tuned to detect unusual traffic patterns originating from WAGO devices during boot.