CVE-2025-44593 is a vulnerability affecting versions of the software product 'Halo' prior to version 2.20.13. The core issue lies in the inadequate file type detection mechanism within the application, which allows attackers to bypass restrictions and upload malicious files, including executable (.exe) and HTML (.html) files. The ability to upload .html files is particularly critical because it can lead to stored Cross-Site Scripting (XSS) vulnerabilities. Stored XSS occurs when malicious scripts are saved on the server and later executed in the browsers of users who access the affected content, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability is resolved in version 2.20.13 of Halo, indicating that the vendor has implemented improved validation or filtering mechanisms to prevent unauthorized file uploads. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability was publicly disclosed on September 9, 2025, with the reservation date being April 22, 2025.

For European organizations using the Halo software, this vulnerability poses a significant risk to both the confidentiality and integrity of their systems and data. The ability to upload malicious executable files could allow attackers to execute arbitrary code on the server, potentially leading to full system compromise. The stored XSS vulnerability introduced by malicious HTML files can be exploited to target users of the application, leading to credential theft, session hijacking, or the spread of malware within the organization. This could result in data breaches, unauthorized access to sensitive information, and disruption of business operations. Organizations in sectors with high regulatory requirements such as finance, healthcare, and government are particularly at risk due to the potential for compliance violations and reputational damage. The absence of known exploits in the wild suggests that proactive patching can effectively mitigate the threat before widespread exploitation occurs.

European organizations should prioritize upgrading the Halo software to version 2.20.13 or later, where the vulnerability has been addressed. Until the upgrade is applied, organizations should implement strict file upload controls, including server-side validation of file types and content inspection to detect and block executable and HTML files. Employing Web Application Firewalls (WAFs) with rules designed to detect and block malicious file uploads and XSS payloads can provide an additional layer of defense. Regular security audits and penetration testing focused on file upload functionalities should be conducted to identify any residual weaknesses. User input sanitization and output encoding should be enforced to mitigate the impact of any stored XSS attacks. Furthermore, monitoring and alerting on unusual file upload activities or execution of unexpected files can help detect potential exploitation attempts early.