An authentication issue was addressed with improved state management. This issue is fixed in iOS 13.2 and iPadOS 13.2, macOS Catalina 10.15.1, tvOS 13.2, watchOS 6.1. A local attacker may be able to login to the account of a previously logged in user without valid credentials..
https://support.apple.com/HT210724
https://support.apple.com/HT210723