New Apple security feature reboots iPhones after 3 days, researchers confirm

> reboots the phone if it’s not unlocked for 72 hours

Scheduled reboots would help more with clearing malware or transient errors.

But for now, for anyone periodically using the phone, which I bet is most users, the phone will never reboot automatically.

Not never; phones also reboot when there are critical OS updates to apply — and that happens as long as the phone is both charging and locked at any time during a vendor-defined daily maintenance window (usually something like 2AM-4AM in the user's local time.)

This happens even if the user just put the phone to sleep a moment ago. The only way to prevent it is to never leave your phone locked and charging at the same time.

> phones also reboot when there are critical OS updates to apply

Of course, or when they run out of battery, or you drop them too hard, etc. But realistically you could go for weeks or months without a reboot. From a transient fault or malware perspective, that might as well be never.

"Critical security updates" for iOS come ~weekly.

> But for now, for anyone periodically using the phone, which I bet is most users, the phone will never reboot automatically.

Samsung has an auto-reboot daily feature and has been pushing it a lot (in form of annoying notifications and settings suggestions). In principle, it may not even be a bad idea - but for one fact:

Rebooting the phone effectively turns it off. Until the user unlocks the phone, it won't connect to phone network. AFAIK it also won't start any of the usual background processes that listen to notifications, and it might not even connect to Wi-Fi.

Those "security" measures make automated reboots an useless feature. There really is only one good time to auto-reboot, and that's when the user is sleeping. But no way anyone's doing that when it means their phone won't be able to receive calls. Even during the day, the phone randomly rebooting and remaining disconnected until the user notices - it's probably even worse, and I imagine anyone would disable this feature after first time it activated.

This is definitely not true. Apple releases security updates about once a month.

I'm not sure this is true.

I have a Samsung with this feature. It rebooted overnight and this morning it was in BFU state with several mail and sms notifications. It was also connected to wifi and the cellular network.

It was true for my Galaxy S22, and is currently true with reboots after update. And yes, early on I had a situation where the phone rebooted overnight and remained stuck on the lock screen while disconnected from networks, until I woke up and noticed. Fortunately I didn't miss anything important, but after that I immediately reviewed all settings and disabled anything that could reboot the device automatically (including updates, which are set for manual installation now).

>>Rebooting the phone effectively turns it off. Until the user unlocks the phone, it won't connect to phone network. AFAIK it also won't start any of the usual background processes that listen to notifications,

Well yes, because the storage and all the apps are encrypted until you unlock your phone. So you could have all the apps boot up and start listening for events, but it would be at the cost of reduced security elsewhere. Not sure what the right solution is tbh, I think personally I'd rather have all of my data encrypted even if it means my phone isn't actually "active" after a reboot.

> Until the user unlocks the phone, it won't connect to phone network.

This is not true in my case (Samsung Galaxy S22+). The phone is fully operational after a reboot, connected to GSM, 5G and Wi-Fi