Updated:02:16 PM EDT Jun 01

this is subsite Google reveals "high severity" flaw in macOS kernel - TechAmok

Google reveals "high severity" flaw in macOS kernel - [security]
11:17 AM EST - Mar,03 2019 - post a comment

A security researcher from Google's Project Zero has discovered that even though macOS' kernel, XNU, allows copy-on-write (COW) behavior in some cases, it is essential that any copied memory is not available for modifications from the source process. While COW is a resource-management technique that is not inherently flawed, it appears that Apple's implementation of it certainly is.

Project Zero has found out that if a user-owned mounted filesystem image is modified, the virtual management subsystem is not informed of the changes, which means that an attacker can potentially take malicious actions without the mounted filesystem knowing about it. The detailed explanation can be found below:

This copy-on-write behavior works not only with anonymous memory, but also with file mappings. This means that, after the destination process has started reading from the transferred memory area, memory pressure can cause the pages holding the transferred memory to be evicted from the page cache. Later, when the evicted pages are needed again, they can be reloaded from the backing filesystem.

This means that if an attacker can mutate an on-disk file without informing the virtual management subsystem, this is a security bug. MacOS permits normal users to mount filesystem images. When a mounted filesystem image is mutated directly (e.g. by calling pwrite() on the filesystem image), this information is not propagated into the mounted filesystem.
The researcher informed Apple about the flaw back in November 2018, but the company is yet to fix it even after exceeding the 90-day deadline, which is why the bug is now being made public with a "high severity" label. That said, Apple has accepted the problem and is working with Project Zero on a patch for a future macOS release. You can also view the proof-of-concept code that demonstrates the problem on the dedicated webpage here.

Short overview of recent news articles

Samsung Odyssey G9 QLED Curve Gaming Monitor (Jun,01 2020 )

TSMC 5 nm+ Node Manufacturing Goes High-Volume in Q4 (May,31 2020 )

SpaceX makes history with launch of astronauts (May,30 2020 )

SpaceX will try again to launch 1st astronaut mission for NASA today (May,30 2020 )

Cricket Launches Two New Nokia Phones (May,29 2020 )

This Ridiculous 5G Signal Blocking USB Stick Is A Complete Scam (May,29 2020 )

Samsung Money is Samsung's Answer to Apple Card (May,28 2020 )

Get Borderlands: The Handsome Collection for Free (May,28 2020 )

AMD Releases Radeon Software Adrenalin 20.5.1 Drivers (May,28 2020 )

Windows 10 May 2020 Update available for download (May,27 2020 )

NVIDIA GeForce 446.14 WHQL driver (May,27 2020 )

NASA and SpaceX Launch Astronauts to Space! (May,27 2020 )

AMD Ryzen 9 3900XT and Ryzen 7 3800XT Benchmarks (May,27 2020 )

YouTuber Attempts To Blow Bubbles With Molten Lava (May,26 2020 )

i9 10900X vs Ryzen 9 3900X Test in 9 Games (May,26 2020 )

Arm Intros Its High-End Processor Designs for 2021 (May,26 2020 )

Fortnite now runs at 90Hz on the OnePlus 8 series (May,26 2020 )

How the Teenage Players of Habbo Hotel Turned to Financial Crime (May,24 2020 )

8 things NOT to do in Germany (May,24 2020 )

Google Launches Suite of New Accessibility Features (May,24 2020 )

Intel Rocket Lake CPU Appears with 6 Cores and 12 Threads (May,23 2020 )

Tenet - new trailer (May,23 2020 )

Xiaomi Mi Band 5 rumored to gain SpO2 sensor (May,23 2020 )

Intel Core i9-10900K hits 7.7GHz on liquid helium (May,21 2020 )

Apple and Google Launch COVID-19 Exposure Notification (May,21 2020 )

T-Mobile Offers Free Service to First Responders (May,21 2020 )

Intel Core i9-10900K Review (May,21 2020 )

Space Force - Official Trailer (May,20 2020 )

THE HOOD INTERNET presents 1986 (May,18 2020 )

The Best Upcoming ACTION Movies 2020 (Trailers) (May,18 2020 )

Da 5 Bloods - Official Trailer (May,18 2020 )

Driver Performs Strange and Dangerous U Turn (May,18 2020 )

Watch This 1,500-HP Honda Civic Go From 0 To 60 MPH In A Crazy 1.1 (May,18 2020 )

Xfinity Mobile Launches 5G Service (May,18 2020 )

Netflix is restoring streaming quality in Europe (May,16 2020 )

TCL-Branded Phones Launch in US on May 19 (May,14 2020 )

GTA V is free on the Epic Games Store (May,14 2020 )

Unreal Engine 5 Revealed! (PS5) (May,13 2020 )

Microwaving a Highlighter Has a Surprising Reaction! (May,12 2020 )

Intel i9-10900K CPU runs very hot & consumes 235W (May,12 2020 )

WhatsApp will soon allow 50 person video calls (May,11 2020 )

All Samsung Galaxy Phones Since 2014 Are Vulnerable (May,10 2020 )

The process of making friends with a carpenter bee (May,09 2020 )

Windows 10 20H1 Update releases on May 26th (May,09 2020 )

Ashes of the Singularity: Escalation for Free (May,08 2020 )

AMD Ryzen 3 3300X and Ryzen 3 3100 Reviews (May,08 2020 )

iOS 13.5 Can Automatically Share Medical Info with 911 Operators (May,08 2020 )

Verizon Launches LG Q70 (May,08 2020 )

BECKY Trailer (2020) Kevin James as Neo-Nazi Thriller Movie (May,07 2020 )

Shit the simpsons really did predict 2020 (May,07 2020 )

>> News Archive <<

TechAmok - Privacy Policy        loading time:0secs