According to Apple’s quite extensive release notes, Catalina 10.15.4 includes extensive improvements. Most notable among these is the introduction of iCloud Drive folder sharing. This had originally been intended to be released in the first version of Catalina, but had to be postponed when there were many problems with it during last summer’s beta testing. This is handled from the Finder, and has controls to limit access, and its own system of permissions.
Screen Time gains two new controls aimed primarily at children’s accounts. One imposes communications limits, and the other playback of music videos. Music has a time-synced lyrics view, the App Store adds support for Universal Purchases and tweaks the Arcade tab. Safari 13.1 can import Chrome passwords, supports HDR playback for Netflix (on compatible hardware).
Among quite a long list of more minor improvements is support for OAuth authentication with Outlook.com accounts, a Dark Mode glitch when copying text between apps, and an issue with screen brightness in the LG UltraFine 5K display when waking from sleep. The Pro Display XDR has new customised reference modes for specific workflows.
Security fixes include: a serious bug in AMFI which allowed arbitrary entitlements, three Bluetooth bugs, access to call history, two kernel bugs, a bug in
sudo which allowed an attacker to run commands as a non-existent user, a bypass to the enforcement of code signing in TCC, and others. Safari 13.1 and WebKit also have multiple security fixes.
One small but significant security update which is bundled with the 10.15.4 update is in the TCC database, which goes from version 150.18 to 150.19. There aren’t any concurrent security updates for once. All models have also undergone firmware update: T2 models should now report a version number of 1037.100.359.0.0 with iBridge of 17.16.14263.0.0,0.
Full listings of current firmware versions following these updates are provided here for Catalina, and here for those running High Sierra or Mojave. They are also used automatically by my free utility SilentKnight, which automatically checks your firmware against its databases. Thanks to Pico for kindly supplying those lists.
Of Apple’s bundled apps, the following have changed version or build numbers in 10.15.4:
- App Store, small build increment
- Books, updated from version 2.2 to 2.4
- Calculator, updated to 10.15.4
- Calendar, small build increment
- Chess, updated to 3.17
- Contacts, small build increment
- Dictionary, small build increment
- Home, build increment
- Mail, updated from 13.0 to 13.4
- Maps, build increment
- Music, updated to 1.0.4
- News, updated to 5.4
- Notes, minor build increment
- Photos, major build increment
- Podcasts, build increment
- Reminders, build increment
- Stocks, updated to 2.4
- TV, updated to 1.0.4
- Bluetooth File Exchange, updated to 7.0.4
- Boot Camp Assistant, build increment
- VoiceOver Utility, build increment.
Safari is updated to version 13.1.
Library files and bundles which have also seen major or extensive updates include:
- Accessibility bundles, minor build increments
- Network Utility, build increment
- Screen Sharing, build increment
- Bluetooth Setup Assistant and BluetoothUIServer, updated to 7.0.4
- DiskImageMounter, updated
- Dock, build increment
- Finder, updated to 10.15.4
- ManagedClient, updated to 12.2
- Photo Library Migration Utility, substantial build increment
- Siri, updated to 200.4.2
- Software Update, substantial build increment
- Spotlight, build increment
- System.kext, updated to 19.4.0
- OSLog framework, build increment
- SwiftUI framework, updated to 42.21.401
- A lot of private frameworks have also been updated.
Support for the APFS file system has been updated from version 1412.81.1 to 1412.101.1.
Standalone updaters are available from: