A port redirection issue was addressed with additional port validation. This issue is fixed in macOS Big Sur 11.2 Security Update 2021-001 Catalina Security Update 2021-001 Mojave tvOS 14.4 watchOS 7.3 iOS 14.4 and iPadOS 14.4 Safari 14.0.3. A malicious website may be able to access restricted ports on arbitrary servers.