CVE-2025-34436 is an authorization bypass vulnerability classified under CWE-639 (Authorization Bypass Through User-Controlled Key) affecting AVideo, a video hosting and streaming platform developed by World Wide Broadcast Network. The vulnerability exists in versions prior to 20.0, where the upload functionality allows authenticated users to place files into directories belonging to other users. Although the system verifies that the user is authenticated, it fails to enforce ownership checks on the target upload directory, resulting in an insecure direct object reference (IDOR). This flaw can be exploited by any authenticated user without additional privileges or user interaction, enabling unauthorized file uploads into other users’ spaces. Such unauthorized uploads could lead to data integrity violations, unauthorized content injection, or potentially facilitate privilege escalation or lateral movement within the system. The CVSS 4.0 base score of 8.7 reflects the vulnerability’s high impact on confidentiality, integrity, and availability, combined with its ease of exploitation (network attack vector, low attack complexity, no privileges required). No public exploits have been reported yet, but the vulnerability’s nature makes it a critical concern for environments relying on AVideo for multi-user content management. The lack of patches at the time of publication necessitates immediate compensating controls to mitigate risk.

For European organizations, especially those in media, education, and corporate sectors using AVideo for video content management, this vulnerability poses significant risks. Unauthorized file uploads into other users’ directories can lead to data tampering, unauthorized content distribution, and potential malware injection. This could compromise the confidentiality and integrity of stored content, damage organizational reputation, and disrupt service availability. In multi-tenant or shared hosting environments common in European universities and media companies, the risk of lateral privilege escalation or data leakage between users is heightened. Additionally, regulatory frameworks such as GDPR impose strict data protection requirements, and exploitation of this vulnerability could lead to compliance violations and financial penalties. The absence of known exploits currently provides a window for proactive mitigation, but the high CVSS score underscores the urgency of addressing the issue to prevent future attacks.

1. Immediately restrict upload permissions to enforce strict ownership validation on the server side, ensuring users can only upload files to their own directories. 2. Implement robust access control checks in the application logic to prevent insecure direct object references. 3. Monitor file upload logs and user activity for anomalies indicating unauthorized access attempts or suspicious file placements. 4. Employ file integrity monitoring to detect unauthorized changes or additions to user directories. 5. Segregate user storage environments where feasible to minimize cross-user access risks. 6. Apply patches or updates from World Wide Broadcast Network as soon as they become available. 7. Conduct regular security audits and penetration testing focused on authorization mechanisms within AVideo deployments. 8. Educate users and administrators about the risks of unauthorized file uploads and encourage prompt reporting of suspicious behavior.