An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 14.2 and iPadOS 14.2, macOS Catalina 10.15.7, Security Update 2020-005 High Sierra, Security Update 2020-005 Mojave. Processing a maliciously crafted USD file may lead to unexpected application termination or arbitrary code execution.
https://support.apple.com/kb/HT211931
https://support.apple.com/kb/HT211930
https://support.apple.com/en-us/HT211929