CVE-2022-3281 is a high-severity vulnerability affecting multiple WAGO industrial automation products, specifically the 750-81xx/xxx-xxx Series PFC100/PFC200 controllers, Series Touch Panel 600, Compact Controller CC100, and Edge Controller. The vulnerability arises from an expected behavior violation categorized under CWE-440, which relates to the loss of intended security controls after certain operations. In this case, the issue is that after a device reboot, the MAC address filtering mechanism—which is designed to restrict network access based on device MAC addresses—is lost or disabled. This failure allows a remote attacker to bypass the MAC address filtering protection and gain unauthorized network access to the device or the network segment it protects. The vulnerability does not require authentication or user interaction and can be exploited remotely over the network, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is primarily on the integrity of the network access controls, potentially allowing unauthorized devices to connect and communicate with the affected controllers. This can lead to unauthorized command injection or manipulation of industrial control processes, which are critical in industrial environments. The vulnerability affects firmware version 03.01.07(13) and possibly other versions, though only this version is explicitly mentioned. No known exploits are currently reported in the wild, and no patches or mitigation links are provided in the source data, indicating that organizations must proactively monitor for vendor updates. The vulnerability is significant because WAGO controllers are widely used in industrial automation, including manufacturing, energy, and infrastructure sectors, where network segmentation and access control are vital for operational security and safety.

For European organizations, this vulnerability poses a substantial risk, especially those operating critical infrastructure, manufacturing plants, or energy distribution systems that rely on WAGO controllers. The loss of MAC address filtering after reboot can allow attackers to infiltrate protected industrial networks, potentially leading to unauthorized control commands, disruption of industrial processes, or data manipulation. This can result in operational downtime, safety hazards, and financial losses. Given the increasing targeting of industrial control systems (ICS) in Europe by cyber adversaries, the vulnerability could be exploited in targeted attacks aiming to disrupt essential services or cause physical damage. The integrity impact is high, as unauthorized network access could lead to malicious control or sabotage. Although availability and confidentiality impacts are not directly indicated, the compromise of control systems can indirectly affect availability and leak sensitive operational data. The lack of authentication and user interaction requirements lowers the barrier for exploitation, increasing the threat level for European organizations using affected WAGO devices.

Organizations should immediately identify and inventory all WAGO devices running the affected firmware version 03.01.07(13) or similar. Until a vendor patch is available, network-level mitigations should be implemented, including strict network segmentation to isolate WAGO controllers from untrusted networks and limit access to only authorized management stations. Deploying additional network access controls such as 802.1X port-based authentication can supplement MAC filtering and prevent unauthorized device connections. Monitoring network traffic for anomalous connections or unauthorized MAC addresses can help detect exploitation attempts. Implementing device hardening measures, such as disabling unnecessary services and enforcing strong network policies, will reduce attack surface. Organizations should also establish a process to apply firmware updates promptly once WAGO releases patches addressing this vulnerability. Incident response plans should be updated to include detection and containment strategies for potential exploitation of this MAC filtering bypass. Regular backups and system integrity checks will aid recovery if compromise occurs.