CVE-2024-33893 identifies a cross-site scripting (XSS) vulnerability in Cosy+ devices, specifically those running firmware versions 21.x below 21.2s10 or 22.x below 22.1s3. The root cause is improper input sanitization when the device displays logs, which allows an attacker to inject malicious JavaScript code. This vulnerability falls under CWE-79, a common web security weakness. The attack vector is network-based (AV:N), requiring no privileges (PR:N), but user interaction (UI:R) is necessary to trigger the malicious script execution. The vulnerability impacts confidentiality and integrity by potentially exposing sensitive information or enabling session hijacking or unauthorized actions within the device’s web interface. Availability is not affected. The vulnerability has a CVSS 3.1 base score of 6.1, categorized as medium severity. No known exploits have been reported in the wild, but the flaw is fixed in firmware versions 21.2s10 and 22.1s3. Cosy+ devices are often used in industrial and critical infrastructure environments, where secure remote access and monitoring are essential. The XSS vulnerability could be leveraged by attackers to compromise device management sessions or pivot into internal networks if combined with other attack vectors. The vulnerability’s scope is limited to affected firmware versions and requires user interaction, reducing the likelihood of widespread automated exploitation but still posing a significant risk in targeted attacks.

For European organizations, especially those in industrial automation, manufacturing, or critical infrastructure sectors using Cosy+ devices, this vulnerability could lead to unauthorized disclosure of sensitive operational data or session hijacking through malicious script execution. Attackers exploiting the XSS flaw could manipulate device logs or user sessions, potentially gaining footholds for further network intrusion or data exfiltration. While availability is not impacted, the compromise of confidentiality and integrity could disrupt operational security and trust in device management. The risk is heightened in environments where these devices are accessible remotely or integrated into broader network management systems. Additionally, regulatory compliance frameworks in Europe, such as NIS2 and GDPR, emphasize the protection of critical infrastructure and personal data, making timely remediation essential to avoid legal and reputational consequences.

European organizations should immediately verify the firmware versions of all deployed Cosy+ devices and upgrade any running versions below 21.2s10 or 22.1s3 to the fixed releases. Network segmentation should be enforced to limit access to device management interfaces, restricting them to trusted internal networks or VPNs. Implement strict input validation and sanitization on any custom interfaces interacting with these devices if applicable. Monitor logs for unusual activity that could indicate attempted XSS exploitation or unauthorized access. Educate users and administrators about the risks of interacting with suspicious log entries or links that could trigger the XSS. Employ web application firewalls (WAFs) where possible to detect and block malicious script injections targeting device interfaces. Regularly audit and update device firmware as part of a robust patch management process. Finally, consider deploying endpoint detection and response (EDR) solutions to identify lateral movement attempts following initial exploitation.