CVE-2025-25084 is a stored cross-site scripting (XSS) vulnerability identified in the antrouss UniTimetable software, affecting all versions up to and including 1.1. The root cause is improper neutralization of user-supplied input during web page generation, which allows malicious scripts to be embedded persistently within the application’s data store. When other users access the affected pages, the malicious scripts execute in their browsers under the context of the vulnerable site. Stored XSS is particularly dangerous because the injected payload is saved on the server and delivered to multiple users, increasing the attack surface and potential impact. Exploitation can lead to session hijacking, credential theft, unauthorized actions, or distribution of malware. Although no public exploits or patches are currently available, the vulnerability has been officially published and reserved under CVE-2025-25084. The lack of a CVSS score requires an independent severity assessment. Given the nature of stored XSS and its potential to compromise user data and system integrity, this vulnerability is considered high severity. UniTimetable is a scheduling and timetable management tool, likely used in educational institutions and organizations requiring resource scheduling, which may increase the value of the target for attackers. The vulnerability demands immediate attention to prevent exploitation once active attacks emerge.

The stored XSS vulnerability in UniTimetable can have significant impacts on organizations worldwide. Attackers exploiting this flaw can execute arbitrary JavaScript in the context of the affected application, potentially stealing session tokens, user credentials, or other sensitive information. This can lead to unauthorized access, privilege escalation, and data breaches. Additionally, attackers may perform actions on behalf of users without their consent, such as modifying schedules or injecting malicious content. The persistent nature of stored XSS means multiple users can be affected, amplifying the damage. For organizations relying on UniTimetable for critical scheduling, disruption or manipulation of data can impact operational efficiency and trust. Furthermore, successful exploitation could serve as a foothold for further attacks within the network. The absence of known exploits currently provides a window for proactive mitigation, but the risk remains high once exploit code becomes available.

To mitigate CVE-2025-25084, organizations should first monitor for any official patches or updates from antrouss and apply them promptly once released. In the absence of patches, implement strict input validation and output encoding on all user-supplied data before rendering it in web pages. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Conduct thorough code reviews and penetration testing focused on input handling and XSS vectors within UniTimetable. Limit user privileges to reduce the impact of potential exploitation and ensure that only trusted users can input data that will be rendered to others. Additionally, educate users about the risks of XSS and encourage the use of security-aware browsing practices. Consider deploying web application firewalls (WAFs) with rules designed to detect and block XSS payloads targeting UniTimetable. Regularly back up data to enable recovery in case of compromise. Finally, maintain vigilant monitoring for unusual activity that could indicate exploitation attempts.