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Even with a burner sim, there is the International Mobile Equipment Identity (IMEI) number, which is tied to the phone, and is known to all apps with the android.permission.READ_PRIVILEGED_PHONE_STATE permission.

exceptione 14 hours ago [ - ]

That can't be true? <https://grapheneos.org/faq#hardware-identifiers>

  As of Android 10, apps cannot obtain permission to access non-resettable hardware identifiers such as the serial number, MAC addresses, IMEIs/MEIDs, SIM card serial numbers and subscriber IDs. Only privileged apps included in the base system with READ_PRIVILEGED_PHONE_STATE whitelisted can access these hardware identifiers. Apps targeting Android 10 will receive a SecurityException and older apps will receive an empty value for compatibility. The currently enabled carrier-based messaging app for SMS/MMS/RCS is a special case that's given access to certain device identifiers including the IMEI. This is normally the GrapheneOS fork of AOSP Messaging but can be changed to another app by the user.

  Since these restrictions became standard, GrapheneOS only makes a small change to remove a legacy form of access to the serial number by legacy apps, which was still around for compatibility. It used to need more extensive changes such as disallowing access to the serial number but those restrictions are now standard.

I don't know however if sandboxed google play is such a privileged app.

asnelt 14 hours ago [ - ]

I couldn't immediately find whether GrapheneOS grants READ_PRIVILEGED_PHONE_STATE to Google Play. It might very well be that the GrapheneOS sandbox spoofs a fake IMEI, and I do hope so.

In any case, my parent comment was meant for stock Pixels, as mentioned by armadyl further up in this thread.

nickspacek 13 hours ago [ - ]

https://grapheneos.org/usage#sandboxed-google-play

> Google Play receives absolutely no special access or privileges on GrapheneOS as opposed to bypassing the app sandbox and receiving a massive amount of highly privileged access.

It doesn't mention IMEI here, but hopefully READ_PRIVILEGED_PHONE_STATE is included in "privileged access."

exceptione 13 hours ago [ - ]

There is an AppStore app, I am not sure if this is the one we are talking about? <https://github.com/GrapheneOS/AppStore/blob/main/app/src/mai...>

That one lists:

  ACCESS_NETWORK_STATE
  ENFORCE_UPDATE_OWNERSHIP
  FOREGROUND_SERVICE
  FOREGROUND_SERVICE_SPECIAL_USE
  INSTALL_PACKAGES
  INTERNET
  POST_NOTIFICATIONS
  QUERY_ALL_PACKAGES
  RECEIVE_BOOT_COMPLETED
  REQUEST_DELETE_PACKAGES
  REQUEST_INSTALL_PACKAGES
  UPDATE_PACKAGES_WITHOUT_USER_ACTION

gruez 13 hours ago [ - ]

That's grapheneos's own app, separate from the play store or play services.

exceptione 12 hours ago [ - ]

True. I think this one is closer to the truth: <https://github.com/GrapheneOS/platform_packages_apps_GmsComp...>

There is no READ_PRIVILEGED_PHONE_STATE mentioned there.

gruez 12 hours ago [ - ]

That's also incorrect, because the gmscompat app is just a helper app. Play services can and does request additional permissions. Those permissions are handled by the OS under the play services app, not gmscompat. If you want RCS for instance, you must grant play services and google messages phone and ICC auth access, which isn't seen in gmscompat at all.

exceptione 11 hours ago [ - ]

  > That's also incorrect, because the gmscompat app is just a helper app.

Hmm, ok. I was reasoning the helper app was needed to get around the default assumptions from Google Play Services.

  >  Those permissions are handled by the OS under the play services app

Yes, but I assume you don't mean that as that GOS makes special hard-coded provisions for the play services. GOS claims to run Play Services like any other unprivileged app, and so any additional permission it would want would have to be consented by the user and should be visible to the user. If not, then GOS wording would be quite a bit unfortunate at least.

EDIT: "GmsCompatConfig is the text-based configuration for the GrapheneOS sandboxed Google Play compatibility layer. It provides a large portion of the compatibility shims." [1] This seems to indicate that the permissions requested by Play Services are being honored with the shims from the helper app. That would alleviate the permission problem.

1. https://github.com/GrapheneOS/platform_packages_apps_GmsComp...

mindslight 13 hours ago [ - ]

That's the application software side. I would assume the IMEI and IMSI are both going out to the cell network though, and I would presume that it's trivial to tie a phone number to those with how the mobile industry generally sells subscriber data to various data brokers. The only question is how permissive those data brokers are (their major constraint is how much most people become aware of this dynamic), but when dealing with a major APT like Google I'd assume they're tuned into the best ones with songs about bona fide purposes.

exceptione 13 hours ago [ - ]

Are you talking about the US here? I am hoping this would be off-limits in Europe.

mindslight 12 hours ago [ - ]

Yes I am talking with a US perspective. I would hope the GDPR would prevent such things in (most of) Europe. But I also personally wouldn't assume so given that there are still the same dynamics of keeping the info flows private to avoid scrutiny, and claiming plausible "legitimate purposes" and "consent".