CVE-2025-57882 is a high-severity vulnerability identified in the firmware of AutomationDirect's CLICK PLUS C0-0x CPU series, specifically affecting the Click Plus C2-03CPU-2 device running firmware version 3.60. The vulnerability is classified under CWE-404, which pertains to improper resource shutdown or release. In this case, the flaw allows an unauthenticated attacker to exploit the Remote PLC application by exhausting all available device sessions. This exhaustion leads to a denial-of-service (DoS) condition, effectively rendering the device unresponsive or unable to process legitimate requests. The vulnerability does not require any authentication or user interaction, increasing its risk profile. The CVSS 4.0 base score of 8.2 reflects a high severity, with an attack vector of network (AV:N), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), and no impact on confidentiality, integrity, or availability directly, but a high impact on availability (VA:H). The lack of known exploits in the wild suggests it is a recently disclosed issue, but the potential for disruption in industrial control systems (ICS) environments is significant. The improper resource release likely stems from the firmware failing to correctly close or free session resources, allowing an attacker to open multiple sessions until the device's capacity is exhausted. This vulnerability is particularly critical in ICS contexts where uptime and reliability are paramount, as the affected devices are used for automation and control in industrial environments.

For European organizations, especially those operating in industrial automation, manufacturing, and critical infrastructure sectors, this vulnerability poses a significant risk. The affected AutomationDirect CLICK PLUS C0-0x CPU devices are commonly deployed in programmable logic controller (PLC) roles, which are integral to process control and automation. A successful DoS attack could halt production lines, disrupt supply chains, or impair critical infrastructure operations such as water treatment, energy distribution, or transportation systems. The unauthenticated nature of the attack vector means that attackers can exploit this vulnerability remotely without needing credentials, increasing the risk of widespread disruption. Given the high attack complexity, exploitation may require some specialized knowledge or conditions, but once exploited, the impact on availability is severe. The lack of confidentiality or integrity impact reduces the risk of data breaches but does not mitigate the operational disruption risk. European organizations with interconnected ICS environments or remote management capabilities are particularly vulnerable, as attackers could leverage network access to launch DoS attacks, potentially causing cascading failures in industrial processes.

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Immediate firmware update: Although no patch links are currently provided, organizations should monitor AutomationDirect's official channels for firmware updates addressing CVE-2025-57882 and apply them promptly. 2) Network segmentation: Isolate PLC devices from general enterprise networks and restrict access to the Remote PLC application to trusted management networks only. 3) Access control: Implement strict firewall rules and intrusion prevention systems (IPS) to limit incoming connections to the affected devices, reducing exposure to unauthenticated attackers. 4) Session monitoring: Deploy monitoring tools to detect abnormal session counts or connection attempts to the PLC devices, enabling early detection of potential DoS attempts. 5) Rate limiting: Where possible, configure network devices or the PLC itself to limit the number of concurrent sessions or connection attempts from a single source. 6) Incident response planning: Prepare and test response procedures for DoS scenarios affecting ICS devices to minimize downtime and operational impact. 7) Vendor engagement: Engage with AutomationDirect support for guidance and to obtain early access to patches or workarounds. These measures go beyond generic advice by focusing on network-level controls, monitoring, and operational preparedness specific to ICS environments.