PSA: Apple isn’t really patching all the safety holes in older variations of macOS

0-day or N-day? It relies upon. —

Massive Sur bought a repair 234 days earlier than Catalina did, though each are supported.

Andrew Cunningham

The default wallpaper for macOS Catalina.

Enlarge / The default wallpaper for macOS Catalina.


Information is making the rounds immediately, each by way of a write-up in Vice and a publish from Google’s Risk Evaluation Group, of a privilege escalation bug in macOS Catalina that was being utilized by “a well-resourced” and “possible state-backed” group to focus on guests to pro-democracy web sites in Hong Kong. In line with Google’s Erye Hernandez, the vulnerability (labeled CVE-2021-30869) was reported to Apple in late August of 2021 and patched in macOS Catalina safety replace 2021-006 on September 23. Each of these posts have extra data on the implications of this exploit—it hasn’t been confirmed, nevertheless it actually seems to be one more entrance in China’s effort to crack down on civil liberties in Hong Kong—however for our functions, let’s deal with how Apple retains its working techniques updated, as a result of that has even wider implications.

On the floor, this incident is a comparatively unremarkable instance of safety updates working as they must. Vulnerability is found within the wild, vulnerability is reported to the corporate that’s answerable for the software program, and vulnerability is patched, all within the house of a few month. The issue, as famous by Intego chief safety analyst Joshua Lengthy, is that the very same CVE was patched in macOS Massive Sur model 11.2, launched all the best way again on February 1, 2021. That is a 234-day hole, even supposing Apple was and continues to be actively updating each variations of macOS.

For context: yearly, Apple releases a brand new model of macOS. However for the good thing about individuals who do not need to set up a brand new working system on day one, or who cannot set up the brand new working system as a result of their Mac is not on the supported {hardware} record, Apple gives security-only updates for older macOS variations for round two years after they’re changed.

This coverage is not spelled out wherever, however the casual “N+2” software program help timeline has been in place because the very early days of Mac OS X (as you’ll be able to think about, it felt way more beneficiant when Apple went two or three years between macOS releases as an alternative of 1 yr). The traditional supposition, and one which I think about when making improve suggestions in our yearly macOS evaluations, is that “supported” means “supported,” and that you simply need not set up a brand new OS and take care of new-OS bugs simply to profit from Apple’s newest safety fixes.

However as Lengthy factors out on Twitter and on the Intego Mac Safety Weblog, that is not all the time the case. He has made a behavior of evaluating the safety content material of various macOS patches and has discovered that there are a lot of vulnerabilities that solely get patched within the latest variations of macOS (and it seems to be like iOS 15 stands out as the similar means, although iOS 14 continues to be being actively supported with safety updates). You possibly can clarify away a few of this disparity—many (although not all!) of the WebKit vulnerabilities in that record had been patched in a separate Safari replace, and a few bugs could have an effect on newer options that are not really current in older variations of the working system. In line with Hernandez, the vulnerability at situation right here did not appear to have an effect on macOS Mojave, regardless of its lack of a patch. However within the case of this privilege escalation bug, now we have an instance of an actively exploited vulnerability that was current in a number of variations of the working system however for months had solely really been patched in certainly one of them.

The straightforward answer for this downside is that Apple ought to really present all of the safety updates for all of the working techniques that it’s actively updating. Nevertheless it’s additionally time for higher communication on this topic. Apple ought to spell out its replace insurance policies for older variations of macOS, as Microsoft does, reasonably than counting on its present hand-wavy launch timing—macOS Mojave’s final safety replace was again in July, for instance, that means that though it was nonetheless officially-unofficially supported till Monterey was launched in October, it missed out on a bunch of safety patches launched for Massive Sur and Catalina in September. Individuals should not should guess whether or not their software program continues to be being up to date.

As Apple leaves an increasing number of Intel Macs behind, it must also think about extending these timelines, if just for Mac {hardware} that’s actually incapable of upgrading to newer macOS releases (there may be precedent for this, as iOS 12 continued to obtain safety updates for 2 years after being changed, however solely on {hardware} that could not improve to iOS 13 or newer). It is not affordable to anticipate Apple to help previous macOS variations in perpetuity, however completely practical Macs should not be in a state of affairs the place they’re two years (or much less) from being completely unpatched if Apple decides to drop them from that yr’s help record.