macOS Catalina 10.15.5 Gets Supplemental Security Update

Together with iOS 13.5.1 and watchOS 6.2.6, Apple has also released a supplemental upgrade for macOS Catalina 10.15.5. The reason is the same, a security fix that patches a vulnerability detected and used by the team behind the ‘unc0ver 5.0’ tool to jailbreak iOS 13.5. It’s a zero-day vulnerability that allows an application to execute arbitrary code with kernel privileges.

macOS Catalina 10.15.5 supplemental update is the 5th ugrade to the macOS Catalina series, launched in the fall of 2019. The same supplemental security update is also available for Mac computers, that aren’t compatible with the Catalina version and are running the earlier macOS High Sierra 10.13.6. Both software updates are downloadable from the Mac App Store, as detailed below.

How To Install macOS Catalina 10.15.5 Supplemental Update
1. Open the Launchpad.
2. Click on System Preferences.
Tip: You can open system preferences directly from the Desktop by clicking the “Apple logo”, top-left corner of the screen and then System Preferences.
3. Select Software Update.
4. Click Update Now and follow the on-screen instructions. The 1,20 GB large update will be downloaded and installed on your Mac.
Fact: The Macbook automatically reboots after the installation process is completed.

macOS Catalina 10.15.5 Supplemental Update Log
The update log doesn’t provide too many details. It informs us that we’re dealing with “important security updates” and that all users should opt for it.
However, if we check the security content we find out that this supplemental update is patching the same security vulnerability used by the ‘unc0ver 5.0’ tool.

“Kernel
Impact: An application may be able to execute arbitrary code with kernel privileges
Description: A memory consumption issue was addressed with improved memory handling.
CVE-2020-9859: unc0ver”

Related: macOS Catalina 10.15.5 most important upgrade is the Battery Health Management feature that has the role to extend the lifespan of the Mac’s battery.