Booked Scheduler 2.5.5 allows authenticated users to create and schedule events for any other user via a modified userId value to reservation_save.php. NOTE: 2.5.5 is a version from 2014; the latest version of Booked Scheduler is not affected. However, LabArchives Scheduler (Sep 6, 2022 Feature Release) is affected.

Open redirect vulnerability in Booked versions prior to 3.3 allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having a user to access a specially crafted URL.

phpscheduleit Booked Scheduler 2.7.5 allows arbitrary file upload via the Favicon field, leading to execution of arbitrary Web/custom-favicon.php PHP code, because Presenters/Admin/ManageThemePresenter.php does not ensure an image file extension.