CVE-2025-34281 is a stored cross-site scripting (XSS) vulnerability identified in ThingsBoard, an open-source IoT platform widely used for device management and data visualization. The vulnerability affects versions prior to 4.2.1 and resides in the dashboard's Image Upload Gallery feature. Specifically, the issue stems from insufficient sanitization of SVG files uploaded by users. SVG files can embed JavaScript code, and because ThingsBoard fails to properly validate the content type and sanitize the SVG content, malicious scripts embedded within these files can execute in the context of the victim’s browser when the dashboard renders the image. This improper neutralization of input during web page generation corresponds to CWE-79. The vulnerability allows an attacker with low privileges to upload a crafted SVG file that, when viewed by other users or administrators, executes arbitrary JavaScript. This can lead to session hijacking, unauthorized actions, or data theft within the ThingsBoard UI. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, but user interaction is needed to trigger the payload. The scope is limited but impacts confidentiality and integrity. No known exploits have been reported in the wild yet, but the vulnerability is publicly disclosed and patched in version 4.2.1. The lack of patch links suggests users must rely on vendor advisories or update notifications. The vulnerability highlights the risks of accepting SVG files without strict sanitization and content-type enforcement in web applications.

For European organizations, especially those relying on ThingsBoard for IoT device management, industrial automation, or smart infrastructure, this vulnerability poses a moderate risk. Successful exploitation could allow attackers to execute malicious scripts within the dashboard interface, potentially leading to session hijacking, unauthorized command execution, or data leakage. This compromises the confidentiality and integrity of operational data and user sessions. Given ThingsBoard’s role in critical infrastructure monitoring and control, such an attack could disrupt operational visibility or lead to further lateral movement within networks. The medium CVSS score reflects moderate impact; however, the actual risk depends on the deployment context and user privileges. Organizations with many users accessing dashboards or with less stringent upload controls are at higher risk. The absence of known exploits reduces immediate threat but does not eliminate future risk. European entities in sectors like manufacturing, energy, and smart cities, where ThingsBoard is commonly deployed, should prioritize remediation to prevent potential exploitation.

1. Upgrade ThingsBoard installations to version 4.2.1 or later, where this vulnerability is patched. 2. Implement strict server-side validation of uploaded SVG files, including sanitization to remove any embedded scripts or potentially harmful content. 3. Enforce content-type validation to ensure only legitimate image files are accepted, rejecting files with suspicious MIME types or extensions. 4. Restrict upload permissions to trusted users only and monitor upload activity for anomalies. 5. Apply Content Security Policy (CSP) headers in the web application to limit the execution of inline scripts and reduce XSS impact. 6. Educate users and administrators about the risks of uploading untrusted files and encourage vigilance when interacting with uploaded content. 7. Regularly audit and monitor ThingsBoard dashboards for unusual behavior or unauthorized content. 8. Consider isolating the dashboard interface or using web application firewalls (WAFs) to detect and block malicious payloads targeting this vulnerability.