Hotel key cards, even invalid ones, help hackers break into rooms

F-Secure researcher Timo Hirvonen shows an Assa Abloy's hotel key card in Helsinki, Finland April 20, 2018. Picture taken April 20, 2018. REUTERS/Attila Cser

HELSINKI: By getting hold of a widely used hotel key card, an attacker could create a master key to unlock any room in the building without leaving a trace, Finnish security researchers said in a study published on April 25, solving a 14-year-old mystery.

While the researchers have fixed the flaw together with Assa Abloy, the world's largest lock manufacturer which owns the system in question, the case serves as a wake-up call for the lodging industry to a problem that went undetected for years.