Brute Forcing A GPS PIN


[JJ] picked up a Garmin Nuvi 780 GPS from an auction recently. One of the more frustrating features [JJ] ran into is it’s PIN code; this GPS can’t be unlocked unless a four-digit code is entered, or it’s taken to a ‘safe location’. Not wanting to let his auction windfall go to waste, [JJ] rigged up an automated brute force cracking robot to unlock this GPS.

The robot is built around an old HP scanner and a DVD drive sled to move the GPS in the X and Y axes. A clever little device made out of an eraser tip and a servo taps out every code from 0000 to 9999 and waits a bit to see if the device unlocks. It takes around 8 seconds for [JJ]’s robot to enter a single code, so entering all 10,000 PINs will take about a day and a half.

Fortunately, the people who enter these codes don’t care too much about the security of their GPS devices. The code used to unlock [JJ]’s GPS was 0248. It only took a couple of hours for the robot to enter the right code; we’d call that time well spent.

You can check out the brute force robot in action after the break.


120 thoughts on “Brute Forcing A GPS PIN

        1. COMMENT FAIL
          “”hack – seek and exploit weaknesses in a computer or computer network.””

          That may be a teenager’s dictionary definition of ‘hacking’, but to those of us that came through the early 70’s – we know and respect the word and activity a lot more than that simple definition.

          Reusing or redefining technology – both hardware and software – to achieve new and unsuspected applications of same. Explore – Learn – Innovate – Share… nothing to do with computers or networks by definition, but if they are in the path of exploration – then so be it

          Just because Facebook says something is a fact – doesn’t make it so!

          1. You missed the point. You claim to have come up in the 70s, making you around 40 to 50 years old, yet you write like a teenager or at best a twenty-something. To put it another way, I was born in the 70s and I don’t say things like “fail” in normal conversation because it’s the vernacular of the kids today. I talk like an adult because that is what I am.

            Maybe you’re young at heart and trying to stay “in” with the teens, but I think it’s more likely you’re just a kid posturing. Either way, it’s kinda lame (something we did say back in the 80s and 90s, BTW).

          2. Good logic, but missed a few key input parameters..
            Hint: I was programming my first micros (2650 & Z80) in the 70s, and was working for Digital (DEC) around 1980 on {PDP-8s and 11s)
            I have kids ranging from 15 to 29, so I’m loosely in touch with teen jargon, but more specifically – the initial comment about hacking showed (lets call it) disrespect for the origins of the hacking ethic – which was in fact ‘ethical’.
            Cheers – I enjoy the sparring, but still wondering how to open a tin of paint !

          3. How could I miss something you didn’t mention until you replied to me? Not a single word about your work experience or family stats in the post I replied to. To expect me to somehow intuit all that detail, just to prop up your claims, is quite silly.

            So much for _your_ logic…

          4. @kaidenshi – no offence intended in my previous posts.
            I was following that you tried to identify my era from my initial post, and was off by a bit. Consequently the teenager/posturing was quite a bit off – although I do admit to being young at heart.(most of the time)

      1. technically he could have went straight for the data stream, and wrote code to brute force through software, but he chose to make a hardware and software approach that is muchh harder, and it’s not ghetto because there was no proper defined way to hack it in the first place, there would have to be a standard first to have a lesser standard

      2. This place has become the youtube community of hacking. Turning a servo into a geared motor is even considered a hack? It’s considered ghetto because why? Because he should have went all out and spent a ton of money and make it look super pretty to essentially accomplish his original goal? The man spent very little with whatever he had laying around to crack through a password protected device. That is, in every sense of the word, a true hacker. You should go back to doing PC case mods.

        1. Does prying open a can of paint with a screwdriver constitute as a hack? I don’t mean to deride [JJ]’s work by any means, I’m just tired of seeing this quip all the time.

          1. Just curious… How do /you/ guys open a paint can ?
            I’ve always used a screwdriver to pry the lid at intervals around the perimeter.
            Is there a better way ?!
            TIP: in the groove of the can lip ( that the tin lid fits into ) – punch 2-3 holes with a 1/16 pin through – which allows excess paint to drain back into the can – but is covered & sealed when the lid is back in place.


    1. I think he just timed the process and set a delay for the successive iteration

      probably once running you can just deactivate the pin protection withouth having to input the old one

      1. You could also put a camera on it and fast forward through the video to get to the part where it unlocks to see the code.
        You could also add some image recognition to do this of course ;)

        1. An itteration counter would be quicker as it is already in software. Just display the current code and stop.
          But for the camera route I would think taking photos would be more of a hack. Two wires attatched to the shutter switch extend the button to a micro switch which is pressed when the cd tray gets to a certain point. maybe even set up a few more switches to erase the previous photo so you don’t have to flick through. :D

    2. I figured I’d let it run without any sort of “check” to see if it unlocked. If it failed or re-locked the device, I would have set up a camera to monitor its progress. Coincidentally I went downstairs to check its progress about 2 hours in, and I witnessed it unlock on “0248”. Pure luck!

      1. Great work! Back in high school, I built a PIC based brute force unlocker for Master combination locks (the ones with the dial face). It used a stepper motor to turn the dial and an actuator to pull on the shackles. This was before I learned that you could just shim the darn things.

    3. there was an update
      “The robot does not currently have any check procedure to see if the device unlocked and will continue to pound the screen even after it unlocks. I figured this may not be a problem, and let it run. I had plans to add a camera to monitor its progress if this does not work or re-locks the device.
      Coincidentally, I went downstairs to check on its progress about 2 hrs in, and I witnessed the unlock with my own eyes!”

    1. i bet once you get in, you’d get to a point in the menu where the button presses would have no effect. However you might need to reset all the settings to get it back to normal.

  1. I had a Nüvi too where the customer forgot the code and the safe location, rendering the device pretty useless. After some various shorting of data lines to GND on the Flash RAM pins, i managed to confuse it, and bypass the check at boot – Hey, there was nothing to lose!

        1. I’ve looked for the unit, but unfortunately it seems like it’s the unit that i’ve given to a family member, and it’s in daily use, so won’t get it back anytime soon. I have two more kicking around, and i’ve opened up those, and unfortunately the memory chips on those are BGA packages, and not TSOP like the one i “Fuzzed” – Crap :-/ It would have been fun to document it on video. Another time i’ll remember to do that when i have the device in-hand!

    1. I saw that one, and it actually inspired me to build this one. Mine can be programmed for different sized devices and different button location for future devices. His solenoids are fixed in place.

  2. Mmmmm. GPS turns up on Ebay, sold off really cheap, locked, and the seller doesn’t know the code…
    He’ll have to send it to the police (or original owner) if it does turn out to be stolen property.

    1. Or it’s someone like me who just got a car with built in navigation and didn’t need the extra hardware and didn’t want to pay extortion-like rates for updated maps.

      1. What, they just “forgot” the code to it when they sold it?

        And the Freight shipper excuse doesn’t ring true – these devices don’t ship with a PIN as standard, so it belonged to someone. At best, someone “lost” it during shipping from one person to another and it turned up on an auction site.

        Was it, per chance, $3?

    2. Or someone like me who on many occasions have found myself on the receiving end of a password/pin prompt for which I do not recall the password/pin to my own device. As the last time I used said device in a capacity that required a pass/pin input was several months previous.

      Your options at that point are trying to brute force your own device which might not be practical if your need is time critical, such as another trip. Preforming a factory reset if a reset is possible. If not writing the device off as a total loss, or selling it cheap on eBay. Which is better, some ROI or a paperweight?

      I’m not saying it’s outside the realm of possibility that it’s stolen but it’s easily equally plausible that it isn’t.

  3. Question.

    The eraser works because it’s a resistive screen, correct? What would one do with a capacitive screen? A grounded sausage? I’d like to know for a similar project.

      1. Don’t the conductive foams require that they be touching your skin as well? For example, I don’t think the conductive foams or “capacitive stylus” accessories will work if you are holding them with gloves on.

        Of course, correct me if I’m wrong.

          1. @Justin –

            I always liked the (‘too good to check’) story about the TV repairman coming round & finding the remains of a pork sausage in the back of the set –

            “Yeah well, We sometimes found it worked better if you put yr finger in there”…

    1. There are a couple of other guys that built similar machines. That one is pretty cool, but I used what I had on hand. Also, mine has the flexibility to program any X coordinate, rather than just 3 points.

  4. Yeah, wish I had one of these for my grandpa, who somehow enabled the PIN protection en-route when he “dropped it”.

    This means a) he didn’t know his pin, and b) his “safe location” was somewhere in the city.

    I think, in the end, he managed to exchange it at the store he bought it, or mailed it to the manufacturer or something.

  5. “Fortunately, the people who enter these codes don’t care too much about the security of their GPS devices. The code used to unlock [JJ]‘s GPS was 0248.”

    I don’t understand the “fortunately” part of this statement. With the only choices being 0000-9999 it seems that 0248 was as good as ANY other choice.

    [JJ] could just as easily started at 9999 and worked down, so the “security” of the device was about as secure as a 4 digit pin can be.

    So I don’t get the point of the sentence.

      1. (Don’t know how to edit my own post!) Instead of counting from 0000 to 9999 just use the “heat map” numbers to speed up the process. That password falls in some of the categories of usual pins: Ascending sequence number, little gaps betwen numbers, etc

    1. Fortunately for people that need to get around passwords, People are stupid. People really on visual patterns. People use common passwords. Since the password is a simple 4 digit pin, and has unlimited retries, he should have tried the common ones first. 1234, 1111, 0000, 0987, 2580, 0248, etc, Same thing with word based passwords. ILoveYou, God, Sex, family names and dates.

  6. Here’s my take – It’s not a ‘hack’, nor are 90% of the projects/things listed here. What it is however, is a really cool tool developed/made, which could also be used for several other cool purposes by any DIY’er. Kudos to the inventor of that cool little robot/cracker/device. It reminds me of tools/devices used to test QA on touch panels. And I love that it was made with servos and clothes pins, simple and easy.

    1. Without wish to decry [jj]’s achievement in any way, there are quite a lot of mechanical brute forcers targeted at Garmins on youtube – Some pretty fast ones with several fingers, even.

      Garmin 4-digit pins seem to be far less memorable than others :(.

    2. >> Here’s my take – It’s not a ‘hack’,

      Really? You’re claiming this is the intended purpose for a DVD drive and an HP scanner?

      I have a feeling if you asked a group of people what a DVD player is for, 98% of them will tell you it’s for playing DVDs, and the remaining 2% giving smartass answers would still not say “to brute force a GPS device password” :P

  7. Beautiful! Next, where is the ATM-sized robot version… LOL but in all seriousness during NYE I wanted to get some cash but was so loaded I must have punched the PIN like 20 times – nothing happened, OMG at the end it just worked…. :) Terrible security.

    1. without looking to in to it , it was said the password is in flash not an eeprom . would be nice if there was a simple i2c eeprom there but chances are he at least looked

      1. well its not exactly to hard to clear any of those with the proper datasheets unless its stored as part of the main IC
        i dont know about these brands but i have reset mine that had a strange SPI eeprom that after i 0’ed it out the whole system reset to factory
        … i tried reading the thing than was just like “NOAP to confusing”

  8. I like it, he had a boring problem that would take forever to do manually so he built a machine, from junk, to do the job for him, if it wasn’t for thinking like this we’ed still be using slaves. And if you put a capacitance glove fingertip on the end of the pencil you can brute force the touch lock on stolen phones. (Not that anyone would steal phones, of course.)

  9. “Fortunately, the people who enter these codes don’t care too much about the security of their GPS devices. The code used to unlock [JJ]‘s GPS was 0248. It only took a couple of hours for the robot to enter the right code; we’d call that time well spent.”

    Are you implying that a code of 9999 is more secure

  10. what is there on a gps unit that you would want to secure? it isnt a pda or cell phone that can hold secrets and gps now isnt the multi thousand dollar devices they once where

    also any halfway decent security will lock down the device if failed attempts more than say 3 to 5 times

    1. There is the Home button, which (if entered accurately) could lead the attacker to your house. Think of the case where the car is stolen, and the thief goes to the GPS Home. Perhaps there’s a garage door opener in the car which gives the thief access to your home and its contents. I know it’s rare but does happen. This is a security issue and a tip to consider entering a nearby but incorrect address into your GPS home feature

    2. I know that I wouldn’t want someone who stole my gps unit (if I had one) to have my home address, friends addresses, work vendor addresses, etc.

      It’s also an easy way to keep young kids from accidentally deleting stuff.

      As far as theft deterent, it might be effective, but I doubt that most theifs would wait for it to power on and then leave it alone if it’s pass protected.

    1. @scott bates — that is well put and i agree 100%

      to others of interest…
      i never seen so much splitting of hairs on a HAD post surrounding the legitimacy of a “hack” — but i am somewhat new to this online community but far from new when it comes to both hardware and software and network hacks.

      it is unfortunate that the true meaning of the word hack has been HACKED by our media. now days it is taboo to even associate oneself with the word. but up till the mid 80’s it meant you were innovative, thought out of the box to accomplish work arounds and fix that which had others at a loss. a software author might send their code to a hacker to have it fixed or us commodore users would figure out how to bankswitch 4 megabyes of RAM on a c=64 computer then use this hardware to hack INTO an establishments computer via a unpublished number we found using a program like phoneman JUST to look around explore but NOT to destroy or deface.

      so while using a screw driver might to open a can of paint might not be considered a hack…. maybe BENDING that same standard flat blade screw driver to be used to open the can of paint MIGHT BE? i believe the small tool i use for opening cans of paint resemble a very short and bent screw driver of sorts.

      as for FAIL and other terms used by teens these days i myself being 44 am often exposed to new words or rather use of words. FAIL SWAG IDK … etc etc IMHO it doesnt mean you are a poser or any way less of an adult to use them but yes you might need to be young at heart to appreciate them and yet responsible enough not to over use them XD

  11. “Fortunately, the people who enter these codes don’t care too much about the security of their GPS devices. The code used to unlock [JJ]‘s GPS was 0248. ”

    How is 0248 any more or less secure than say 9999 or 5248? Every guess has the same probability of being correct. Or are you assuming all attackers are going to enter codes sequentially starting at 0000?

    1. I wonder if any body supplies a “brick” option for passwords. The brick option could be set to a random location above and below the entered password. Brute force cracking would likely hit a “brick” password before the legit password and brick the device.

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