Chamilo LMS is an open-source learning management system. In versions prior to 2.0.0-RC.3, the notebook module contains an Insecure Direct Object Reference (IDOR) vulnerability that allows any authenticated student to read the private course notes of any other user on the platform by manipulating the notebook_id parameter in the editnote action. The application fetches the note content using only the supplied integer ID without verifying that the requesting user owns the note, and the full title and HTML body are rendered in the edit form and returned to the attacker's browser.

While ownership checks exist in the write paths (updateNote() and delete_note()), they are entirely absent from the read path (get_note_information()). This issue has been fixed in version 2.0.0-RC.3.