CVE-2025-44593 is a medium-severity vulnerability affecting versions of the Halo software prior to 2.20.13. The core issue lies in the inadequate file type detection mechanism that allows attackers to bypass restrictions and upload malicious files, including executable (.exe) and HTML (.html) files. The ability to upload HTML files is particularly concerning because it can lead to stored Cross-Site Scripting (XSS) attacks (CWE-79). Stored XSS occurs when malicious scripts are saved on the server and executed in the browsers of users who access the affected content, potentially leading to session hijacking, credential theft, or other malicious activities. The vulnerability does not require authentication (PR:N) but does require user interaction (UI:R), such as a victim visiting a malicious page or content. The attack vector is network-based (AV:N), meaning exploitation can be attempted remotely. The vulnerability impacts confidentiality and integrity but not availability, as indicated by the CVSS vector (C:L/I:L/A:N). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. Although no known exploits are currently reported in the wild, the presence of stored XSS and file upload bypass capabilities makes this a significant risk if left unpatched. The vulnerability was fixed in Halo version 2.20.13, so updating to this or later versions is critical to remediation.

For European organizations using Halo software, this vulnerability poses a risk of unauthorized code execution within user browsers, potentially leading to data theft, session hijacking, and unauthorized actions performed on behalf of users. Organizations in sectors with high web application usage, such as finance, healthcare, and government, are particularly at risk due to the sensitivity of data handled. The ability to upload executable files also raises concerns about malware distribution or further compromise of internal networks if these files are executed or distributed internally. Given the vulnerability can be exploited remotely without authentication, attackers could target public-facing Halo instances to gain a foothold or escalate privileges. The stored XSS aspect could also be leveraged for phishing or social engineering campaigns targeting European users. The medium CVSS score (6.1) reflects a moderate but tangible threat, especially in environments where user interaction with the application is frequent and security controls are insufficient.

1. Immediate upgrade to Halo version 2.20.13 or later to apply the official patch that fixes the file type detection bypass. 2. Implement strict server-side validation of uploaded files, including MIME type verification and content inspection, to prevent malicious files from being accepted. 3. Employ Content Security Policy (CSP) headers to limit the impact of any potential XSS by restricting script execution sources. 4. Sanitize and encode all user-generated content before rendering it in browsers to mitigate stored XSS risks. 5. Monitor file upload logs and web application logs for unusual activity or attempts to upload disallowed file types. 6. Conduct regular security assessments and penetration testing focused on file upload functionalities. 7. Educate users about the risks of interacting with suspicious content and encourage reporting of anomalies. 8. If possible, isolate the Halo application environment to limit lateral movement in case of compromise.