Apple’s older operating systems are updated regularly to patch security vulnerabilities. Apple also said that only the latest operating system updates are fully protected.
Apple has not previously specified its security update practices. It takes enterprising users and researchers to compare security patch notes and CVE numbers to determine what gets patched.
According to a new support document reported by Ars Technica, Apple says that only the most comprehensive security patches are available for the latest operating systems. On older systems, vulnerabilities will still be patched, but not all of them.
The support document is meant to define the difference between software updates and upgrades, but information about security patches is also included. It briefly mentions that older macOS versions are not as protected as the latest major system versions.
Not surprising for those who follow the industry. Apple will patch serious problems with operating systems that are years old, but not every patch will be universally applied.
For the average user, the best way to stay protected from vulnerabilities is to use the latest hardware and update to the latest available software. However, not every user will be able to upgrade their operating system as soon as the latest and greatest version is rolled out.
Some users will still stick with an older operating system. For example, as devices age, they lose the ability to run the latest software and are officially dropped from support for new upgrades.
For devices that can run the latest software, users sometimes decide to wait for a stable version to arrive, or for work-related applications to become compatible. Even when a new operating system has been introduced, Apple tends to release a small number of support updates for older systems.
For example, Apple recently released iOS 15.7.1, which includes a number of security fixes and patches. However, this update covers a smaller list of vulnerability entries than iOS 16.1.