I accidently clicked on an advertisement, and opened it with chrome. It was one of those things where you can subscribe to an App Store for £4.50 a week for apps which are usually free anyway.

This is the app screen (left) with app permissions (right):

                     enter image description here                    enter image description here

App screen shows the last six digits of my mobile number at the bottom.

And this was the URL:


How can I fix this security problem?

  • Where was this advert? In another Chrome tab or in an app? If the advert knew your phone number, it could easily pass it in the URL.
    – schroeder
    Aug 19, 2015 at 0:30
  • The fact that any site can see my phone number. And the advert was in MX player.
    – George
    Aug 19, 2015 at 0:31
  • But what if the site was passed your phone number from the MX player? In that case, Chrome knows nothing but what it was told by the advertiser.
    – schroeder
    Aug 19, 2015 at 0:35
  • It's the advert, as MX has several different Ads in it.
    – George
    Aug 19, 2015 at 0:39
  • 4
    It is likely that you gave that app permission to know your phone ID and number as part of the permissions. The app then passed that information along to the advertiser. The fix is to revoke those permissions.
    – schroeder
    Aug 19, 2015 at 0:40

1 Answer 1


The permissions for the Chrome app for Android show that it has access to Identity. Therefore it is able to see your phone number.

Unfortunately Android, differently from iOS, does not allow natively to fine-grain installed apps' permissions (it's more an "accept everything or don't install this app" philosophy). I've read about some wrapper applications such as MoboClean that allow to do this, but I haven't tried them myself. UPDATE: Android 6.0 Marshmallow introduced fine-grained permissions, which make you able to choose which specific permission to grant to an application.

  • Not all permissions can be revoked, though. Only a handful of permissions(high-risk ones) can be revoked from any app.
    – pri
    Feb 6, 2017 at 10:35
  • Correct. For instance, you cannot block an app to access the network: android.stackexchange.com/questions/138311/…
    – dr_
    Feb 6, 2017 at 10:40

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