The Master Lock hack: cracking the combo in eight tries or less

If you use a Master combination lock at the gym, you might need to reconsider it after reading this post. Because if other gym-goers are also reading this, your belongings may not be as secure as you think.

(Or, if you have a lock lying around but you’ve long forgotten the combination, this is how to figure it out.)

According to Ars Technica:

“There’s a vulnerability in Master Lock branded padlocks that allows anyone to learn the combination in eight or fewer tries, a process that requires less than two minutes and a minimal amount of skill to carry out.”

“Serial hacker” Samy Kamkar figured out the technique after fiddling with a previously known vulnerability that allowed the locks to be cracked in less than 100 tries.

With his eight-tries-or-less hack, all you need is a locked Master Lock and access to Kamkar’s online combination calculator.

Follow his simple instructions for determining the combination here, or watch the above video tutorial.

After watching the video, Ars staffers attempted the hack on their own Master Locks. While their attempts at the challenge eventually worked “after some refinement” — one hacker found that finding the third number in the equation was the trickiest — they discovered that older locks weren’t cooperating with the hack.

So if your Master Lock is from 1985, you’re probably safe from hackers. For now.

Here are the hack instructions. Try it at home. And let us know if you were able to crack the code!