CVE-2021-1884

A race condition was addressed with improved locking. This issue is fixed in Security Update 2021-004 Mojave, iOS 14.5 and iPadOS 14.5, watchOS 7.4, Security Update 2021-003 Catalina, tvOS 14.5, macOS Big Sur 11.3. A remote attacker may be able to cause a denial of service.

Source: CVE-2021-1884