An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 13.3.1 and iPadOS 13.3.1, macOS Catalina 10.15.3, tvOS 13.3.1, watchOS 6.1.2. An application may be able to gain elevated privileges.
https://support.apple.com/HT210921
https://support.apple.com/HT210920