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.

Popular Stories

Alleged iPhone 17 Pro Antenna Design

Two All-New iPhone 17 Colors Seemingly Confirmed

Monday August 25, 2025 4:22 am PDT by
Apple will offer the upcoming iPhone 17 Pro and iPhone 17 Pro Max in a new orange color, according to Bloomberg's Mark Gurman. Gurman made the claim in the latest edition of his Power On newsletter, adding that the new iPhone 17 Air – replacing the iPhone 16 Plus – will come in a new light blue color. We've heard multiple rumors about a new iPhone 17 Pro color being a shade of orange. The ...
AirPods Pro 3 Heart Rate Tracking Feature

AirPods Pro 3 Expected to Launch This Year With Key New Feature

Sunday August 24, 2025 7:16 am PDT by
Bloomberg's Mark Gurman expects Apple to release new AirPods Pro this year, and he said the earbuds will have a key new feature: heart rate monitoring. From his Power On newsletter today, with emphasis added:As for Apple's other devices, there's a lot in the fall pipeline — though many of the new products are only incremental upgrades. There will be Apple Watch updates, faster Vision...
iPhone 17 Pro on Desk Centered 1

iPhone 17 Pro Coming Soon With These 12 New Features

Sunday August 24, 2025 6:00 am PDT by
Apple's iPhone 17 Pro and iPhone 17 Pro Max should be unveiled in a few more weeks, and there are plenty of rumors about the devices. In his Power On newsletter today, Bloomberg's Mark Gurman corroborated a rumor that iPhone 17 Pro models will be "available in an orange color." Below, we recap key changes rumored for the iPhone 17 Pro models: Aluminum frame: iPhone 17 Pro models are...
Awe Dropping Apple Event Feature

Five Things to Expect From Apple's 'Awe Dropping' September 9 Event

Tuesday August 26, 2025 4:17 pm PDT by
Apple today announced its "Awe Dropping" iPhone-centric event, which is set to take place on Tuesday, September 9 at 10:00 a.m. Pacific Time. There are a long list of products that are coming, but we thought we'd pull out five feature highlights to look forward to. That Super Thin iPhone - Apple's September 9 event will see the unveiling of the first redesigned iPhone we've had in years, ...
iPhone 17 Pro Dark Blue and Orange

iPhone 17 Release Date, Pre-Orders, and What to Expect

Thursday August 28, 2025 4:08 am PDT by
An iPhone 17 announcement is a dead cert for September 2025 – Apple has already sent out invites for an "Awe dropping" event on Tuesday, September 9 at the Apple Park campus in Cupertino, California. The timing follows Apple's trend of introducing new iPhone models annually in the fall. At the event, Apple is expected to unveil its new-generation iPhone 17, an all-new ultra-thin iPhone 17...
awe dropping event

Apple Event Announced for September 9: 'Awe Dropping'

Tuesday August 26, 2025 9:01 am PDT by
Apple will hold its annual iPhone-centric event on Tuesday, September 9 at the Apple Park campus in Cupertino, California, according to an announcement that went out today. The event will start at 10:00 a.m., with select members of the media invited to attend. At the September 2025 iPhone event, Apple will unveil the iPhone 17 lineup, which includes an all-new ultra-thin iPhone 17 Air. It...
iPhone 17 Air Thumb 2 Blue Electric Boogaloo

Apple Has Reportedly Considered Releasing iPhone 17 Air Bumper Case

Sunday August 24, 2025 12:40 pm PDT by
Apple has "considered" releasing a bumper case for the upcoming iPhone 17 Air, according to Bloomberg's Mark Gurman. Similar to the bumper case that Apple introduced for the iPhone 4 in 2010, Gurman said the iPhone 17 Air version of the case would cover the edges of the device, but not the back of it. Those bumper cases were made of rubber. Given that the iPhone 17 Air is expected to have ...
Awe Dropping Apple Event Feature

Apple Event Logo Hints at Two iPhone 17 Pro Features

Wednesday August 27, 2025 6:36 am PDT by
Apple's logo for its upcoming September 9 event hints at two rumored iPhone 17 Pro features, including new color options and a vapor chamber cooling system. Of course, this is all just speculation for fun, as we count down the final days until the event. New Colors Last month, Macworld's Filipe Espósito reported that orange and dark blue would be two out of the five color options...

Top Rated Comments

pier Avatar
100 months ago
What about El Capitan and Sierra?
Score: 35 Votes (Like | Disagree)
alex00100 Avatar
100 months ago
I'd still replace my battery just to be sure ;)
Score: 27 Votes (Like | Disagree)
RoobyRoobyRoo Avatar
100 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
100 months ago
Anyone know if this applies to security-patches for Sierra / El Capitan?
Score: 10 Votes (Like | Disagree)
CrashX Avatar
100 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
100 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)