Mozilla software developer Cody Brocious recently discovered two vulnerabilities within Onity's locks. Brocious was able to exploit said vulnerabilities with a device that cost him $50 to build. The schematics for the device are open source and available on the Web. Brocious will present his findings at the Black Hat Security Conference in Las Vegas on Tuesday night.

Onity tells PCWorld that it is aware of Brocious' work, but has declined to comment until it reviews additional information on the hack itself.

"Onity is prepared to address any potential issues posed by the presentation," a spokesperson said.

The company's locks are found on between four and five million hotel room doors worldwide. Brocious' device plugs into the DC port that is found on the bottom of the outside portion of the lock.

"[It] looks like a standard DC power port you'd see on something like a router," Brocious says. When the device is plugged in and powered up, it will, in theory, cause the door to unlock. The hack simulates a device used by hotel room operators to program locks to accept certain master keys. The hacking device reads the lock's memory, obtains the cryptographic key information, and then sends that information to the door lock, allowing the hacker to gain entry to the room.