CVE-2024-37396 is a stored cross-site scripting (XSS) vulnerability identified in the Calendar function of REDCap version 13.1.9. REDCap (Research Electronic Data Capture) is a widely used secure web application for building and managing online surveys and databases, often employed in academic, clinical, and research environments. The vulnerability allows an authenticated user to inject arbitrary web scripts or HTML code into the 'Notes' field of a calendar event. Because the payload is stored, it executes whenever the calendar event is viewed by any user with access, potentially enabling malicious scripts to run in the context of the victim's browser session. This can lead to session hijacking, unauthorized actions performed on behalf of the user, data theft, or the delivery of further malware. The vulnerability requires the attacker to have authenticated access, which limits exploitation to users with some level of legitimate access to the REDCap instance. However, given REDCap's use in sensitive research and healthcare data environments, the impact of such an attack can be significant. The recommended remediation is to update REDCap to version 14.2.1 or later, where the vulnerability has been addressed. No known exploits are reported in the wild as of the publication date, but the high severity rating indicates the potential for serious impact if exploited.

For European organizations, particularly those in healthcare, academic research, and clinical trial sectors where REDCap is commonly deployed, this vulnerability poses a significant risk. Exploitation could lead to unauthorized access to sensitive personal health information (PHI) and research data, violating GDPR and other data protection regulations. The ability to execute arbitrary scripts could also facilitate lateral movement within the network, privilege escalation, or the deployment of ransomware or other malware. The stored nature of the XSS means multiple users could be affected once the malicious payload is injected, amplifying the potential damage. Additionally, reputational harm and regulatory penalties could result from data breaches stemming from this vulnerability. Given the criticality of data handled by REDCap, the impact on confidentiality and integrity is particularly concerning, while availability may also be indirectly affected if systems are compromised or taken offline for remediation.

European organizations using REDCap should prioritize upgrading to version 14.2.1 or later immediately to remediate this vulnerability. Until the update is applied, implement strict access controls to limit authenticated user permissions, especially restricting calendar event creation and editing to trusted personnel only. Conduct thorough input validation and sanitization on the 'Notes' field at the application level if possible, to detect and block malicious payloads. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing REDCap. Regularly audit calendar events for suspicious or unexpected content. Enhance monitoring and logging to detect anomalous user behavior that could indicate exploitation attempts. Educate users about the risks of XSS and encourage vigilance when interacting with calendar events. Finally, ensure that incident response plans include scenarios involving web application XSS attacks to enable rapid containment and remediation.