A logic issue existed resulting in memory corruption. This was addressed with improved state management. This issue is fixed in iOS 13.5 and iPadOS 13.5, macOS Catalina 10.15.5, tvOS 13.4.5, watchOS 6.2.5. A malicious application may be able to execute arbitrary code with kernel privileges.
https://support.apple.com/HT211175
https://support.apple.com/HT211171