A vulnerability was found in SourceCodester Online Hotel Reservation System 1.0. It has been classified as critical. Affected is the function doCancelRoom/doCancel/doConfirm/doCancel/doCheckin/doCheckout of the file /marimar/admin/mod_room/controller.php. The manipulation of the argument id leads to sql injection. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.