Intel Memory Access Design Flaw Already Addressed by Apple in macOS 10.13.2

A serious design flaw and security vulnerability discovered in Intel CPUs has reportedly already been partially addressed by Apple in the recent macOS 10.13.2 update, which was released to the public on December 6.

12 inch macbook macbook pro duo
According to developer Alex Ionescu, Apple introduced a fix in macOS 10.13.2, with additional tweaks set to be introduced in macOS 10.13.3, currently in beta testing. AppleInsider also says that it has heard from "multiple sources within Apple" that updates made in macOS 10.13.2 have mitigated "most" security concerns associated with the KPTI vulnerability.

Publicized yesterday, the design flaw in Intel chips allows normal user programs to see some of the contents of the protected kernel memory, potentially giving hackers and malicious programs access to sensitive information like passwords, login keys, and more.

Full details on the vulnerability continue to be unavailable and under embargo, so it's not yet clear just how serious it is, but fixing it involves isolating the kernel's memory from user processes using Kernel Page Table Isolation at the OS level. Implementing Kernel Page Table Isolation could cause a performance hit on some machines.

According to The Register, which first shared details on the vulnerability, Windows and Linux machines will see a 5 to 30 percent slowdown once a fix is in place. It appears Macs may not be hit as heavily, as no noticeable performance slowdowns have been reported since the launch of macOS 10.13.2.

Ionescu also says that performance drop on a system with PCID (Process-Context Identifiers), available on most modern Macs, is "minimal," so most users may not see an impact on day-to-day Mac usage.

Top Rated Comments

pier Avatar
77 months ago
What about El Capitan and Sierra?
Score: 35 Votes (Like | Disagree)
alex00100 Avatar
77 months ago
I'd still replace my battery just to be sure ;)
Score: 27 Votes (Like | Disagree)
RoobyRoobyRoo Avatar
77 months ago
Erm...no, 10.13.2 has been out for quite a bit, almost a month ago.

Might have even been in earlier beta's as well.
So quick that it happened in the past! I like this new time-bending Apple.
Score: 13 Votes (Like | Disagree)
SecuritySteve Avatar
77 months ago
Anyone know if this applies to security-patches for Sierra / El Capitan?
Score: 10 Votes (Like | Disagree)
CrashX Avatar
77 months ago
For anyone interested, using the Potts-Kant benchmarks on the latest releases of both concurrent versions of Mac OS -

We're running benchmark processes concurrently with PCID disabled, employing supplementary reservoir matching sequences throughout our lab here at Duke.

The testing has just begun - so I'll be posting the results here in about an hour, for anyone interested in how their machines might be affected.

Students have been instructed to take the machines through a variety of real world tests -

So we'll be posting that, as well as the conclusive results provided by our benchmark studies - to hopefully help clear the air and provide a more balanced issuance of the possible affections of data-protected kernel-modeling architecture implications.
Score: 9 Votes (Like | Disagree)
belvdr Avatar
77 months ago
What do we make of this really? I think someone should do a comparative test on handbrake or anything that solely uses CPU and only then we can tell the difference between 10.13.2 and any previous versions of macOS
This has nothing to do with CPU utilization. Rather, you will see a performance penalty when an applications makes system calls, such as to files or network access. Essentially it occurs when ring 3 needs to access something at the more privileged ring 0.
Score: 8 Votes (Like | Disagree)

Popular Stories

iOS 17

26 New Things Your iPhone Can Do With Next Month's iOS 17.2 Update

Wednesday November 22, 2023 10:57 pm PST by
Apple made the first beta of iOS 17.2 available to developers in October. Since then we've seen two more betas, and with each iteration Apple continues to add more new features and changes, many of which users have been anticipating for quite a while. Below, we've listed 26 new things that are coming to your iPhone when the finalized version is publicly released in December. 1. Help You...
Apple Watch Series 9

5 Reasons to Wait for Next Year's Apple Watch

Friday November 24, 2023 3:46 am PST by
With all the discounted deals on Apple tech currently available, you might be thinking about upgrading your Apple Watch or buying one for the first time. But if your current smartwatch is doing its job just fine and it's only the idea of a good deal that's piqued your interest, it could be worth holding out until next year when Apple unveils its latest and greatest version. There are already ...
General Black Friday Deals 2022 Green

40+ Apple Black Friday Deals Still Available for AirPods, iPhone, iPad and More

Friday November 24, 2023 5:01 am PST by
Black Friday 2023 has officially ended, but we're still tracking some of the best deals of the year on Apple products like AirPods, iPad, iPhone, MacBook, and many more. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment, which helps us keep the site running. Specifically, in this article we're...
Cyber Monday Deals Feature 2022

40+ Apple Cyber Week Deals for AirPods, iPad, Apple Watch, and More

Sunday November 26, 2023 9:47 am PST by
Cyber Week has taken the place of Black Friday, and you'll find some of the same deals still around for the next few days, although many from Black Friday have now expired. This includes dozens of record low prices on Apple products like AirPods, iPad, Apple Watch, MacBook, iPhone, and more. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a...
ipad mini 2021 youtube

What to Expect From the Next iPad Mini Later in 2024

Friday November 24, 2023 1:00 pm PST by
Over 800 days have passed since Apple last updated the iPad mini, as outlined in the MacRumors Buyer's Guide. Fortunately, a new iPad mini is rumored to be released next year, and we have outlined what to expect from the device below. Apple released the current iPad mini in September 2021, with new features at the time including a larger 8.3-inch display, a USB-C port, a Touch ID power...