Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Server and starting in version 22.0.0 and prior to versions 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Enterprise Server, an attacker could enable and disable the birthday calendar for any user on the same server. Nextcloud Server 25.0.11, 26.0.6, and 27.1.0 and Nextcloud Enterprise Server 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 contain patches for this issue. No known workarounds are available.
The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.7.1 via the 'attempt_delete' function due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with Instructor-level access and above, to delete arbitrary quiz attempts.
Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Broken access control allows a user to delete attachments of other users. There are currently no known workarounds. It is recommended that the Nextcloud Deck app is upgraded to 1.6.5 or 1.7.3 or 1.8.2.