Android's 5.x Lock Screen may be bypassed by attackers

Martin Brinkmann
Sep 16, 2015
Updated • May 22, 2018
Google Android
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10

Android devices may be protected by a lock screen which requires some form of authentication before access to most phone features, its settings and the data stored on it is granted.

Users may protect the phone by password, pin or pattern for example, and there are other means of protection available as well, for instance by using Bluetooth device authentication or unlocking it based on locations you are in.

If you have set a password on your Android device and you are running Android 5.x, your phone is vulnerable to a lockscreen bypass attack.

The attack itself is surprisingly easy to carry out:

  1. Open the Emergency Call screen on the phone.
  2. You need to enter a long number there with lots of chars. The researchers suggested to start with 10 asterisks and then doubling these characters using copy and paste until this is no longer possible (the field is not highlighted anymore).
  3. Go back to the homescreen afterwards and open the camera application on the device.
  4. Swipe down to display the notifications drawer and tap on  settings. This opens a password prompt automatically.
  5. Paste the same characters that you used in the Emergency Dialer into the password field. Repeat this process until the UI crashes (the buttons at the bottom of the screen disappear and the camera is displayed fullscreen.
  6. The camera will crash eventually as well and the homescreen is displayed. The phone is unlocked and you have full access to all apps and data on it.

android lock password bypass attack

This attack works only if a password is used to protect the Android device. It won't work with pattern or pin locks. If you are using a password-based lock currently you may want to switch to pin or pattern-based instead for the meantime to protect your device from this attack.

The following video demonstrates the attack.

The Android developers have fixed the issue already but it takes time before the fix lands on affected devices.

Attackers need to have physical access to the device to carry out the attack. While that is a limitation, it is still recommended to not use password-based locks on Android 5.x devices until the vulnerability has been patched on affected devices.

Summary
Android's 5.x Lock Screen may be bypassed by attackers
Article Name
Android's 5.x Lock Screen may be bypassed by attackers
Description
Android 5.x devices may be vulnerable to a lockscreen bypass attack if a password is used to protect the device from unauthorized access.
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Comments

  1. Albert said on August 18, 2023 at 1:49 pm
    Reply

    Thanks for the tip Martin.

    It is for these kinds of posts that I follow GHacks.

    1. Mike Williams said on August 26, 2023 at 8:55 pm
      Reply

      What’s up with the generic comment, are you a bot?

  2. Tachy said on August 18, 2023 at 3:23 pm
    Reply

    2G?

    Where on the planet is that still in use? I was forced to give up using my RAZRV3 years ago because 2G was phased out by AT&T.

    1. arbuz said on August 20, 2023 at 5:02 pm
      Reply

      Everywhere 3G has been turned off and you don’t have LTE coverage, and believe me there are many developed countries where this is the case and if it weren’t for 2G you wouldn’t even be able to make a phone call.

    2. Doc Fuddled said on August 31, 2023 at 5:55 pm
      Reply

      Maybe I missed it, but I don’t believe tha term “2G” is in the article. Perhaps you are referring to “AGM G2”??

  3. Tachy said on August 18, 2023 at 3:27 pm
    Reply

    @Martin

    Your website has gone insane.

    When I the post button I then saw my comment posted on a different article page. When I opened this article again, it is here.

    1. Martin P. said on August 31, 2023 at 4:39 pm
      Reply

      @Tachy @Martin Brinkmann

      ” Your website has gone insane. ”

      Same here. Has happened several times.

      1. owl said on September 1, 2023 at 3:42 am
        Reply

        @Tachy,
        @Martin P.,

        For over two weeks now,
        I’ve been seeing “Comments” posted by subscribers appearing in different, unrelated articles.
        https://www.ghacks.net/windows-11-update-stuck-fixed-for-good/#comment-4572991
        https://www.ghacks.net/windows-11-update-stuck-fixed-for-good/#comment-4572951
        For the time being,
        it would be better to specify the “article name and URL” at the beginning of the post.

  4. Anonymous said on August 18, 2023 at 11:17 pm
    Reply

    @tachy a lot of non-phone devices with a sim in them rely on 2G, at least here in europe.
    Usually things reporting usage or errors/alarms on something remote that does not get day to day inspection in person. They are out there in vast numbers doing important work. Reliable, good range. The low datarate is no problem at all in those cases.
    3G is gone or on its last legs everywhere, but this stuff still has too much use to cancel.

    Anyhow, interesting that they would put that in. I can see the point if you suspect a hostile 2G environment (amateur eavesdroppers with laptop, ranging up to professional grade MITM fake towers while “strangely” not getting the stronger crypto voip 4G because it is being jammed, and back down to something as old ‘stingray’ devices fallen into the wrong hands).

    But does this also mean that they have handled and rolled out a fix for that nasty 4G ‘pwn by broadcast’ problem you reported earlier this year? I had 4G disabled due to that, on the off chance that some of the local criminals would buy some cheap chinese gear, download a working exploit and probe every phone in range all over town in the hope of getting into phones of the police.

  5. Andy Prough said on August 19, 2023 at 3:04 am
    Reply

    >”While most may never be attacked in stingrays, it is still recommended to disable 2G cellular connections, especially since it does not have any downsides.”

    The downside would be losing connectivity. I spend a lot of time way out in the countryside where there’s often no service or almost none. My network allows 2G, and I need it sometimes. I have an option on the phone to disable 2G, I may do that when I’m in the city and I have good 5G connectivity, but not out in the country.

    I would imagine that the stingray exploits, like most of the bad things in this world, are probably things you will run into in the crowded big cities.

  6. owl said on August 21, 2023 at 3:40 am
    Reply

    I stopped using it in a mobile (Wi-Fi line) environment, so I’m almost ignorant of the actual situation,
    But the recent reality in Japan makes me realize that “the infrastructure of the web is nothing more than a papier-mâché fiction”.
    https://www.ghacks.net/2023/08/17/google-chrome-to-enable-https-first-by-default-for-all-users/#comment-4572402

    It is already beyond the scope of what an individual can do.
    What we should be aware of is the reality that “governments and those in power want to control the world through the Web”, and efforts to counter (resist and prevent) such ambitions are necessary.

  7. Anonymous said on August 26, 2023 at 9:27 pm
    Reply

    Why do you want people to disable the privacy features? Hmmmmm?

  8. Anonymous said on August 27, 2023 at 2:30 am
    Reply

    Now You: do you plan to keep the Ads privacy features enabled?

    I’d like to tell you, but apparently if you make a post critical of Google, you get censored. * [Editor: removed, just try to bring your opinion across without attacking anyone]

  9. Tachy said on August 27, 2023 at 5:15 am
    Reply

    @Martin

    You website is still psychotic. Comments attach to random stories.

  10. John G. said on August 28, 2023 at 2:46 pm
    Reply

    @Martin please do fix the comments, it’s completely insane commenting here! :[

  11. ECJ said on August 28, 2023 at 5:37 pm
    Reply

    @Martin

    The comments are seriously messed up on gHacks now. These comments are mixed with the article at the below URL.

    https://www.ghacks.net/2023/08/18/android-how-to-disable-2g-cellular-connections-to-improve-security/

    And comments on other articles are from as far back as 2010.

  12. Naimless said on August 29, 2023 at 12:57 am
    Reply

    What does this article has anything to do with all the comments on this article? LOL I think this Websuite is ran by ChatGPT. every article is messed up. Some older comments from 2015 shown up in recant articles, LOL

  13. Paul Knight said on August 31, 2023 at 3:35 am
    Reply

    The picture captioned “Clearing the Android Auto’s cache might resolve the issue” is from Apple Carplay ;)

  14. Anonymous said on August 31, 2023 at 9:57 pm
    Reply

    How about other things that matter:
    Drop survival?
    Screen toughness?
    Degree of water and dust protection?

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