BlueSpiceUserManager: Missing authorization in REST endpoints for blocking and unblocking users

Missing Authorization vulnerability in Hallo Welt! GmbH BlueSpice (Extension:BlueSpiceUserManager) allows any authenticated user without special privileges to block or unblock arbitrary user accounts, including administrators. The REST endpoints /bs-usermanager/v1/block/create and /bs-usermanager/v1/block/delete call UserManager::blockUser() and UserManager::unblockUser(), which do not verify the permissions of the acting user. This allows locking out all administrators (denial of service) and lifting blocks imposed by administrators.

This issue affects BlueSpice: from 5.0.0 before 5.1.11, from 5.2.0 before 5.2.7.