A resource exhaustion issue was addressed with improved input validation. This issue is fixed in iOS 13.1 and iPadOS 13.1, macOS Catalina 10.15. Parsing a maliciously crafted iBooks file may lead to a persistent denial-of-service.Referenceshttps://support.apple.com/en-us/HT210634https://support.apple.com/en-us/HT210603
