Doesn’t Apple and Google on the OS level only allow push notifications to come from its own services? Like, they look for the signature to be compatible with https certificate etc. Otherwise the phone could have a ton of push notifications incoming from anywhere on the Internet. The APN service for instance would only route notifications to a phone if it came from a registered website. How do you get around this?
As far as I know, even for VOIP permissions, iOS only wakes your code up if ITS APNS SERVICE sends the notification. How are you able to install a long-lived application in the background on iOS?
Similarly, the phone radio is listening for calls from the nearby cell towers in the network, not from absolutely any tower. I guess a Stingray can impersonate one, but they would probably need to fake the attestation, right?