Hotel check-in terminal bug spews out access codes for guest rooms

A self-service check-in terminal used in a German Ibis budget hotel was found leaking hotel room keycodes, and the researcher behind the discovery claims the issue could potentially affect hotels around Europe. The terminal's security flaw could be abused by anyone, requiring no technical knowledge or specialized tooling. Realistically, an attacker could aggregate an array of room keycodes in just a few minutes – as long as it would take a regular customer to use the same machine to check in to their room. Self-service check-in terminals can be used by hotel guests as an alternative to speaking with front desk staff, who sometimes aren't available to serve. As well as allowing guests to check into their rooms, these terminals also offer the capability to search for information about existing bookings. If, for example, a guest forgets their keycode, they can input their booking reference number and the terminal will present details about their booking, including their room code. Martin Schobert at Swiss security firm Pentagrid discovered that an attacker could input a series of six consecutive dashes (------) in place of a booking reference number and the terminal would return an extensive list of room details. "Any other sequence of dashes is accepted if it is long enough to enable the submit button," he said. "Therefore, it is assumed that a variable length string is likely not a master code, but a bug or a not deactivated test function." Once the dashes were entered, the bo...