• Development

  • Apps without any permissions can still receive data from the Internet

I believe that this topic has been discussed a few times already but unfortunately I didn't see any mitigation actions being taken on this yet. It seems to me that this is rather concerning.

I'm referring to the situation that there is currently no way to block the communication of one app to other apps. In this way, apps can essentially actively undermine the removal of the "Network" permission and still receive information from the Internet when Google Play Services are installed and online. I wonder if apps can even send information back through the same channel. If yes, I would rate this as a severe privacy risk.

Example:
I have a banking authentication app for which I removed all the permissions (no Network, no Notifications etc.). When I start the login process on the bank website and open the banking authentication app, the app shows a popup asking me to confirm the login. As I understand, my banking app is still able to communicate with Google Play Services. So, when I start the app it probably asks Google Play "Do you have anything for me?" and then Google Play forwards the login confirmation request to the app.
(side note: my original intention is to keep this specific banking authentication app completely offline and only rely on the time-based (OTP-like) codes it generates and not on those authentication popups)

Proposed solution:
Build a mechanism in GrapheneOS where the user can define for each app, with which other apps it is allowed to communicate or whether no communication is allowed at all.

    graphy442556 When I start the login process on the bank website and open the banking authentication app, the app shows a popup asking me to confirm the login. As I understand, my banking app is still able to communicate with Google Play Services. So, when I start the app it probably asks Google Play "Do you have anything for me?" and then Google Play forwards the login confirmation request to the app.

    Yes. This is how Android is designed to work in a general sense and how the banking app in particular was written to work.

    graphy442556 Proposed solution:
    Build a mechanism in GrapheneOS where the user can define for each app, with which other apps it is allowed to communicate or whether no communication is allowed at all.

    The most-likely result (especially for banking apps) is that the banking app will fail. If that is the desired outcome, it might be simpler to just not install the banking app?

    Is it possible to provide more detail on how blocking IPC would improve your ability to run apps that require IPC?

        graphy442556 im not sure if my question applies, but have you tried isolating the google play & authentification app setup? e.g. separate profile

          They spoke about it in the chat as if is planned for later but i'm not sure about the timeline if there is any, for now if i had to use it i would put them in a different profile or maybe in private space profile or work profile if it work