CVE-2025-54962 is a medium severity vulnerability identified in the OpenPLC Runtime version 3, specifically in the webserver component's /edit-user endpoint. This vulnerability is classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. Authenticated users can exploit this flaw to upload arbitrary files, including potentially malicious file types such as .html or .svg. Once uploaded, these files become publicly accessible under the /static URI path. The vulnerability allows an attacker with valid credentials to bypass file type restrictions and place files on the server that could be used for various malicious purposes, such as hosting malicious scripts, phishing pages, or injecting client-side code that could lead to further compromise of users interacting with the OpenPLC web interface. The CVSS v3.1 base score is 6.4, indicating a medium severity level. The vector string (AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N) shows that the attack can be performed remotely over the network with low attack complexity, requires low privileges (authenticated user), no user interaction, and impacts confidentiality and integrity with a scope change, but does not affect availability. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability affects OpenPLC Runtime 3, a platform used for industrial control systems (ICS) and programmable logic controllers (PLCs), which are critical components in industrial automation environments.

For European organizations, especially those operating in industrial sectors such as manufacturing, energy, utilities, and critical infrastructure, this vulnerability poses a significant risk. OpenPLC is used to manage and automate industrial processes, and unauthorized file uploads could lead to the deployment of malicious web content that compromises the confidentiality and integrity of the control environment. Attackers could leverage this to conduct phishing attacks on operators, inject malicious scripts to manipulate control data, or facilitate lateral movement within the network. Although availability is not directly impacted, the compromise of confidentiality and integrity in ICS environments can lead to operational disruptions, safety hazards, and regulatory non-compliance. Given the interconnected nature of industrial networks in Europe and the increasing adoption of Industry 4.0 technologies, exploitation of this vulnerability could have cascading effects on production lines and critical services. The requirement for authentication limits the attack surface to insiders or compromised accounts, but the low complexity and remote exploitability increase the risk if credential management is weak.

European organizations using OpenPLC Runtime should implement the following specific mitigations: 1) Immediately audit user accounts and enforce strict access controls to limit authenticated users to trusted personnel only. 2) Implement multi-factor authentication (MFA) to reduce the risk of credential compromise. 3) Monitor and restrict file upload functionality by applying server-side validation to enforce strict file type and content checks, ideally blocking all file types except those explicitly required and safe. 4) Configure webserver permissions to isolate uploaded files and prevent execution of uploaded content, for example by disabling script execution in the /static directory. 5) Employ web application firewalls (WAFs) with custom rules to detect and block suspicious upload attempts. 6) Conduct regular security assessments and penetration testing focused on the web interface and file upload mechanisms. 7) Maintain network segmentation to isolate the OpenPLC environment from broader corporate networks, limiting potential lateral movement. 8) Stay alert for vendor patches or updates addressing this vulnerability and apply them promptly once available. 9) Implement logging and alerting on file upload activities to detect anomalous behavior early.