Security concern: To provide a visually appealing transition when launching or leaving an application, iOS introduced a feature that automatically captures a screenshot of the current view when an app is moved to the background. This screenshot is subsequently displayed as a preview in the App Switcher.
There is security concern that the app shows sensitive information like activation codes or chat histories in the preview image of the App Switcher
Need clarification on the following points:
1.Where exactly are these App Switcher preview screenshots stored on the device filesystem?
2.Can these App Switcher snapshots be accessed on a jailbroken iOS device?
3.Are these snapshots stored inside the application container or in a system-managed location outside the app sandbox?
- Can any Third party application or tool can access this screenshots in iOS device?
5.Is there any Apple-recommended API, entitlement, or platform-supported mechanism on iOS to prevent screenshots in iOS
1.Where exactly are these App Switcher preview screenshots stored on the device filesystem?
I'm not sure, as I've never specifically looked for them.
2.Can these App Switcher snapshots be accessed on a jailbroken iOS device?
Yes, that's very likely.
3.Are these snapshots stored inside the application container
No.
or in a system-managed location outside the app sandbox?
Yes.
Can any Third party application or tool can access this screenshots in iOS device?
Ignoring jail broken device, no.
5.Is there any Apple-recommended API, entitlement, or platform-supported mechanism on iOS to prevent screenshots in iOS
Sure. SwiftUI has the privacySensitive(_:) view modifier, which basically handles this automatically. UIKit apps typically handled this using a different view to hide their actual view, triggered by either resignation or backgrounding.
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Kevin Elliott
DTS Engineer, CoreOS/Hardware
