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Intel Chips Have Memory Access Design Flaw and Fix Could Lead to Performance Drop

A serious design flaw and security vulnerability has been discovered in Intel's CPUs that will require an update at the operating system level to fix, reports The Register (https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/). All modern computers with Intel chips from the last 10 years appear to be affected, including those running Windows, Linux, and macOS.





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Similar operating systems, such as Apple's 64-bit macOS, will also need to be updated - the flaw is in the Intel x86 hardware, and it appears a microcode update can't address it. It has to be fixed in software at the OS level, or go buy a new processor without the design blunder.

Full details on the vulnerability aren't yet known as the information is currently under embargo until later in the month. The Register has unearthed some data, however, and it seems the bug allows normal user programs to see some of the contents of the protected kernel memory.





This means malicious programs can potentially, in a worst case scenario, read the contents of the kernel memory, which can include information like passwords, login keys, and more. It's not yet clear how severe the bug is, but The Register speculates that it's significant given the rapid changes being made to Windows and Linux.

At worst, the hole could be abused by programs and logged-in users to read the contents of the kernel's memory. Suffice to say, this is not great. The kernel's memory space is hidden from user processes and programs because it may contain all sorts of secrets, such as passwords, login keys, files cached from disk, and so on. Imagine a piece of JavaScript running in a browser, or malicious software running on a shared public cloud server, able to sniff sensitive kernel-protected data.

To fix the bug, the kernel's memory needs to be isolated from user processes using Kernel Page Table Isolation, which could cause a performance hit on some machines. According to The Register, Linux and Windows machines will see a 5 to 30 percent slowdown once the fix is in place.





It's not yet clear how Macs will be impacted, as there is little information available at this time. Software updates are in the works for Linux and Windows, and though not mentioned, Apple is also likely working on a fix for the issue.





Full details on what's known about the vulnerability can be found at The Register (https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/), and additional information will be available later this month when complete details on the design flaw are shared.

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Source: Intel Chips Have Memory Access Design Flaw and Fix Could Lead to Performance Drop (https://www.macrumors.com/2018/01/02/intel-chip-design-flaw/)