Everything On The Intel, AMD & ARM CPU Bug! Rev. 4.0

The speculative execution CPU bug that the Google Project Zero team discovered is arguably the worst CPU bug in history. That’s because it affects many modern CPUs we use today. Not just from Intel, but also CPUs made by AMD, Apple and ARM.

Let’s take a look at what we know so far about this CPU bug, how it affects you, and what we can do about it. We will also share with you details of the Meltdown and Spectre exploits that have successfully targeted this CPU bug.

This story is still developing. We will update the article as and when new details emerge. Be sure to check back and refresh the page for the latest information!

Everything We Know About The Intel, AMD & ARM CPU Bug!

2018-01-16 : Updated the list of vulnerable processors, and added a new section on Intel CPUs spontaneously rebooting after applying Meltdown and Spectre patches. Also added cautionary advice on holding off these updates.

2018-01-12 : Updated the article with the AMD confirmation that their processors are vulnerable to both Spectre 1 and Spectre 2 exploits. Also added details on the Google Retpoline mitigation technique against Spectre attacks.

2018-01-11 : Added new sections on the performance impact of the Meltdown and Spectre mitigation patches, and reports of those patches bricking some AMD PCs. Also expanded the list of affected CPUs, and corrected information on the Intel-SA-00086 Detection Tool.

Between 2018-01-09 and 2018-01-10 : Numerous updates including details of patches and affected CPUs.

Originally posted @ 2018-01-09

 

The Speculative Execution CPU Bug

  • The Project Zero team identified this CPU bug in 2017, reporting it to Intel, AMD and ARM on 1 June 2017.
  • This CPU bug allows the speculative execution feature of the Intel, AMD and ARM processors to be exploited.
  • There are THREE (3) variants of the speculative execution CPU bug :
    • Variant 1 : Bounds Check Bypass (CVE-2017-5753)
    • Variant 2 : Branch Target Injection (CVE-2017-5715)
    • Variant 3 : Rogue Data Cache Load (CVE-2017-5754)
  • The Spectre attack (whitepaper) exploits variants 1 and 2.
  • The Meltdown attack (whitepaper) exploits variant 3.
  • There is a Variant 3a, which appears to affect only certain ARM processors.

 

How Bad Is This CPU Bug?

  • The Spectre attack lets the attacker access and copy information from the memory space used by other applications.
  • The Meltdown attack lets the attacker copy the entire physical memory of the computer.
  • Unless patched, the affected processors are vulnerable to malware and cyberattacks that exploits this CPU bug to steal critical information from running apps (like login and credit card information, emails, photos, documents, etc.)
  • While the Meltdown exploit can be “fixed”, it is likely that the Spectre exploit cannot be fixed, only mitigated, without a redesign of the processors. That could mean we may have to live with the risks of a Spectre attack for many more years to come.

 

What Processors Are Affected? Updated!

For the complete list of affected AMD, Apple, ARM and Intel processors, please see this separate article – The Complete List Of CPUs Affected By Meltdown / Spectre

  • The Speculative Execution CPU Bug Variant 1, targeted by the Spectre exploit, has been confirmed to affect these AMD, ARM and Intel processors :
    • AMD EPYC family of processors
    • AMD Ryzen Threadripper family of processors
    • AMD Ryzen family of processors
    • AMD Opteron family of processors (from 2011 onwards)
    • AMD FX-series processors (from 2012 onwards)
    • AMD A-series APUs (from 2012 onwards)
    • Apple A4, A5, A5X, A6, A6X, A7, A8, A8X, A9, A9X, A10 Fusion, A10X Fusion and A11 Bionic SoCs.
    • ARM Cortex-A75, Cortex-A73, Cortex-A72, Cortex-A57, Cortex-A17, Cortex-A15, Cortex-A9, Cortex-A8, Cortex-R8, and Cortex-R7 processors
    • 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th Gen Intel Core processors
    • Intel Core X-series processors
    • Intel Xeon 3400, 3600, 5500, 5600, 6500 and 7500 series
    • Intel Xeon E3, E3 v2, E3 v4, E3 v5 and E3 v6 family
    • Intel Xeon E5, E5 v2, E5 v3 and E5 v4 family
    • Intel Xeon E7, E7 v2, E7 v3 and E5 v4 family
    • Intel Xeon Phi 3200, 5200, 7200 series
    • Intel Xeon W processors
    • Intel Pentium G processors
    • Intel Atom C, E, A, Z and x3 series processors
    • Intel Pentium N and J series processors
    • Intel Celeron G, N and J series processors
  • The Speculative Execution CPU Bug Variant 2, targeted by the Spectre exploit, has been confirmed to affect these AMD, ARM and Intel processors :
    • AMD EPYC family of processors
    • AMD Ryzen Threadripper family of processors
    • AMD Ryzen family of processors
    • AMD Opteron family of processors (from 2011 onwards)
    • AMD FX-series processors (from 2012 onwards)
    • AMD A-series APUs (from 2012 onwards)
    • ARM Cortex-A75, Cortex-A73, Cortex-A72, Cortex-A57, Cortex-A17, Cortex-A15, Cortex-A9, Cortex-A8, Cortex-R8, and Cortex-R7 processors
    • 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th Gen Intel Core processors
    • Intel Core X-series processors
    • Intel Xeon 3400, 3600, 5500, 5600, 6500 and 7500 series
    • Intel Xeon E3, E3 v2, E3 v4, E3 v5 and E3 v6 family
    • Intel Xeon E5, E5 v2, E5 v3 and E5 v4 family
    • Intel Xeon E7, E7 v2, E7 v3 and E5 v4 family
    • Intel Xeon Phi 3200, 5200, 7200 series
    • Intel Xeon W processors
    • Intel Pentium G processors
    • Intel Atom C, E, A, Z and x3 series processors
    • Intel Pentium N and J series processors
    • Intel Celeron G, N and J series processors
  • The Speculative Execution CPU Bug Variant 3, targeted by the Meltdown exploit, has been confirmed to affect only Intel processors and one ARM processor :
    • ARM Cortex-A75
    • 1st, 2nd, 3rd, 4th, 5th, 6th, 7th and 8th Gen Intel Core processors
    • Intel Core X-series processors
    • Intel Xeon 3400, 3600, 5500, 5600, 6500 and 7500 series
    • Intel Xeon E3, E3 v2, E3 v4, E3 v5 and E3 v6 family
    • Intel Xeon E5, E5 v2, E5 v3 and E5 v4 family
    • Intel Xeon E7, E7 v2, E7 v3 and E5 v4 family
    • Intel Xeon Phi 3200, 5200, 7200 series
    • Intel Xeon W processors
    • Intel Pentium G processors
    • Intel Atom C, E, A, Z and x3 series processors
    • Intel Pentium N and J series processors
    • Intel Celeron G, N and J series processors
  • The Speculative Execution CPU Bug Variant 3a, targeted by the Meltdown exploit, has been confirmed to affect only some ARM processors :
    • ARM Cortex-A72, Cortex-A57 and Cortex-A15 processors
  • To summarise, vulnerable Intel and ARM processors are affected by all three variants of the bug, while vulnerable AMD processors are only affected by the first two variants.
  • Apple confirmed that “all Mac systems and iOS devices are affected“. The only exception – the Apple Watch models are not affected.
  • Although initially saying that their processors are only affected by Spectre 1, AMD clarified on 11 January 2018 that their processors are also affected by Spectre 2.

For the complete list of affected AMD, Apple, ARM and Intel processors, please see this separate article – The Complete List Of CPUs Affected By Meltdown / Spectre

 

Intel Detection Tool

The Intel-SA-00086 Detection Tool does NOT detect the processor’s susceptibility to Meltdown or Spectre. It only checks for different vulnerabilities affecting the Intel Management Engine.

 

What Is Being Done??? Updated!

Note : The terms “mitigate” and “mitigation” mean the possibility of a successfully attacked are reduced, not eliminated.

  • Intel has started issuing software and firmware updates for the processors introduced in the last 5 years. By the middle of January 2018, Intel expects to have issued updates for more than 90% of those CPUs. However, that does not address the other Intel processors sold between 2010 and 2012.
  • Microsoft and Linux have started to roll our the KPTI (Kernel Page Table Isolation) patch, also known as the KAISER (Kernel Address Isolation to have Side-channels Efficiently Removed) patch.
  • The KPTI or KAISER patch, however, will only protect against the Meltdown exploit. It has no effect on a Spectre attack.
  • Microsoft Edge and Internet Explorer 11 received the KB4056890 security update on 3 January 2018, to prevent a Meltdown attack.
  • Firefox 57 includes changes to mitigate against both Meltdown and Spectre attacks.
  • Google Chrome 64 will be released on 23 January 2018, with mitigations against Meltdown and Spectre attacks.
  • For Mac systems, Apple introduced mitigations against Meltdown in macOS 10.13.2 (released on 8 January 2018), with more fixes coming in macOS 10.13.3.
  • For iOS devices, Apple introduced mitigations against Meltdown in iOS 11.2 and tvOS 11.2.
  • On 8 January 2018, Apple released iOS 11.2.2, which mitigates the risk of the two Spectre exploits in Safari and WebKit, for iPhone 5s, iPad Air, and iPod touch 6th generation or later.
  • ARM has made available the KPTI / KAISER kernel patches for Linux, while Google will provide them for Android.
  • Google patched Android against both Spectre and Meltdown exploits with the December 2017 and January 2018 patches.
  • Google shared details of their Return Rrampoline (Retpoline) binary modification technique that can be used to protect against Spectre attacks. It is a software construct that ensures that any associated speculative execution will “bounce” (as if on a trampoline) endlessly.
  • On 11 January 2018, AMD announced that the “majority of AMD systems” have received the mitigation patches against Spectre 1, albeit some older AMD systems got bricked by bad patches. They also announced that they will make “optional” microcode updates available for Ryzen and EPYC processors by the same week.
  • In the same 11 January 2018 disclosure, AMD also shared that Linux vendors have started to roll out OS patches for Spectre 1 and Spectre 2, and they’re working on the “return trampoline (Retpoline)” software mitigations as well.

 

Some AMD PCs Got Bricked

In the rush to mitigate against Meltdown and Spectre, Microsoft released Windows 10 patches that bricked some AMD PCs. They blamed the incorrect / incomplete documentation provided by AMD.

You can read more about this issue @ Warning : These Windows 10 Updates Are Bricking AMD PCs!

 

Some Intel CPUs Spontaneously Reboot New!

Intel’s rush to patch Meltdown and Spectre resulted in buggy microcode patches, causing several generations of their CPUs to spontaneously reboot. If you have one of the affected CPUs, please hold off the Meltdown and Spectre updates!

You can read more about this issue @ Intel Reboot Issues With Meltdown-Spectre Patches

 

What Should You Do?

First and foremost – DO NOT PANIC. There is no known threat or attack using the Meltdown or Spectre exploits.

Although we have listed a number of important Meltdown and Spectre updates below, the number of buggy updates are worse than the potential threat they try to fix. So we advise HOLDING OFF these patches, and wait for properly-tested versions a few weeks down the line.

  • If you are using Windows, make sure you install the KB4056890 security update.
  • If you are using a Mac system, get updated to macOS 10.13.2.
  • If you are using an iOS device, get updated to iOS 11.2 or tvOS 11.2.
  • If you are using Firefox, update to the latest Firefox 57.
  • If you are using Google Chrome, make sure you watch out for Chrome 64, which will be released on 23 January.
  • Download and install the latest software firmware updates from your PC, laptop, motherboard brands. In particular, install the latest driver for the Intel Management Engine (Intel ME), the Intel Trusted Execution Engine (Intel TXE), and the Intel Server Platform Services (SPS)
  • If you are running an ARM processor on Linux, grab the kernel patches.

 

The Performance Impact Of The CPU Bug Patches

Many benchmarks have been released, showing performance impacts of between 5% to 30%, depending on the type of benchmark and workload. Microsoft has called those benchmark results into question, stating that they did not cover both operating system and silicon microcode patches.

They have just released an initial report on their findings, which we have summarised in our article – Pre-2016 Intel CPUs Hit Worst By Meltdown + Spectre Fix.

 

Meltdown + Spectre Reading Suggestions

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  1. Pingback: Daily Roundup: 2018-01-05 - Bjorn3D.com

  2. Arthur

    the tool Intel-SA-00086 Detection Tool is for Intel Management Engine vulnerability, no for Meltdown and Spectre vulnerability

    Reply
  3. Pingback: The Complete List Of CPUs Affected By Meltdown / Spectre - Tech ARP

  4. Pingback: Warning : These Windows 10 Updates Are Bricking AMD PCs! - Tech ARP

  5. Pingback: Yes, AMD CPUs Are Also Vulnerable To Spectre 2 Exploit - Tech ARP

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