Open almost any hotel room in the world for under $50

For less than $50, a hacker can exploit a security flaw in a keycard door lock used by hotels worldwide and berak into up to four million hotel rooms, a tech site said Tuesday night.

BitDefender reported security researcher Cody Brocious, 24, demonstrated the flaw at a BlackHat pre-briefing, exploiting the flaw in the electronic part of the Onity locking system.

"Even though the keycard system uses advanced encryption for the password, the specific model exposes a DC port that can access the device’s memory where the chunk of data (the master key) responsible for unlocking is stored. This DC port allows an electronic programmer to read and write the door lock’s memory space, which is exactly what Brocious did with his device," it said.

In effect, the device can be tricked into opening the door for unauthorized users through the 5-volt DC port it exposes.

“With how stupidly simple this is, it wouldn’t surprise me if a thousand other people have found this same vulnerability and sold it to other governments,” BitDefender cited a Forbes article quoting Brocious.

BitDefender said Brocious plugged into the DC port a home-made electronic key programmer similar to what hotel staff use to program doors.

Yet, he used a device built from parts one can buy at a radio supply store for less than $50.

BitDefender said that while the hack may not work every time in real-life scenarios, there is still a chance of having a door open without an authorized key.

It said Onity, the maker of the device in question, "should learn from the hack is that advanced encryption is useless if you don’t regulate which ports can read what."

"And there’s no need to re-think the entire system or change four million locks overnight – one just needs a good old piece of thick brass shield over the exposed port to make things right again," it added. — TJD, GMA News