Kernel Memory Issue - Spectre/Meltdown

Posted: Friday 5 January 2018 by Chris

You may be aware of the global Kernel Memory Leakage issue relating to CPU vendors which was announced to the public yesterday by international media. 

We have outlined all you need to know below and are actively working with our hardware vendors and operating system vendors to assess impact and remedial action.

We will be updating you further as information becomes available, please be assured that we are doing everything possible to remediate any potential impacts immediately. 

What is the issue?

On Jan 4th, it was announced in the media (theregister.co.uk) that numerous industry wide vulnerabilities in Intel, ARM and AMD (alleged) CPU's had been identified in relationship to Kernel Memory Leakage, known as Meltdown and Spectre. These vulnerabilities impact all compute running Windows, Linux, macOS (including server OS) and operating systems will require a patch to resolve the vulnerabilities.  These vulnerabilities allow for side channel exploits in rogue malicious applications to be able to read data stored on a computers system memory.  It is yet unknown the impact of the operating systems patch on operating system performance, however we will continue to monitor our platforms and make the necessary adjustments where needed. 

Am I affected by the vulnerability?

Yes. This is a global issue with CPU chip sets. The full extent of the impact is yet to be established and we will communicate further as more information is received. Right now, we are doing everything possible by working with our vendors to rectify and remedy the known vulnerabilities.

What could be leaked?

If your system is affected by a malicious application, an exploit could read the memory content of the host server. This may include passwords and sensitive data stored on the system.

An attacker able to execute code with user privileges, can gain access to data in memory space, thus bypassing KASLR: (kernel address space layout randomization). This is a defence mechanism used by various operating systems to place components of the kernel in randomized locations in virtual memory. 

Which systems are affected?

Desktop, Laptop, and Cloud computers may be affected by Meltdown/Spectre. More technically, every Intel (and potentially ARM and AMD) processor which implements out-of-order execution is potentially affected, which is effectively every processor since 1995 (except Intel Itanium and Intel Atom before 2013).

What is the difference between Meltdown and Spectre?

Meltdown breaks the mechanism that keeps applications from accessing arbitrary system memory. Consequently, applications can access system memory. Spectre tricks other applications into accessing arbitrary locations in their memory. Both attacks use side channels to obtain the information from the accessed memory location. For a more technical discussion we refer to the papers (Meltdown and Spectre).

  • Meltdown is Intel-only and takes advantage of a privilege escalation flaw allowing kernel memory access from user space, meaning any secret a computer is protecting (even in the kernel) is available to any user able to execute code on the system. 
  • Spectre applies to Intel, ARM, and AMD processors and works by tricking processors into executing instructions they should not have been able to, granting access to sensitive information in other applications’ memory space.

Is there more technical information about Meltdown and Spectre?

Yes, there is an academic paper and a blog post about Meltdown, and an academic paper about Spectre. Furthermore, there is a Google Project Zero blog entry about both vulnerabilities.

 

=== Update 8/1/2018 ===

Vendors have started to classify the risk impact on their products and are slowly releasing patches remediating some of the vulnerabilities.  We will be patching our cloud server environment with the recommended baseline versions for protection.  Once the final fixes are made available, we will be deploying them accordingly.

If you see browser updates, we strongly recommend that you run these and as per usual, we strongly recommend checking, and applying operating system security updates as they become available.

Web Browser patches:

Firefox: https://www.mozilla.org/en-US/security/advisories/mfsa2018-01/

Google Chrome: https://www.chromium.org/Home/chromium-security/ssca

Microsoft Edge / Internet Explorer: Patches were made available Wednesday last week, but automatic updates will run from next patch cycle.

 

=== Update 12/1/2018 ===

In response to the global Kernel Memory Leakage vulnerability issues that have circulated throughout the last week, we have worked closely with our hardware and operating system vendors to initiate remedial actions.  

As there is no single fix to cover all the variants of Meltdown and Spectre, we are completing our patching in a phased approach, as outlined below.

Cloud Server Platform

  • Our Cloud Server virtualisation platform has been patched up to the current vendor issued baseline.
  • There are 2 remaining specific patches which are pending. These depend on the availability of a vendor firmware patch, which we expect to be released in the coming days.

Infrastructure Hardware

  • The majority of our vendors have already released firmware patches, and patching is in progress.
  • For the few still outstanding we are actively tracking availability with the vendor.
  • For hardware that does not have applicable firmware patches, we are also patching the overlying Operating Systems for additional mitigation.  

Operating System Patches    

  • Microsoft have released patches for Windows Operating Systems. Over 50% of our systems are already patched, with the remaining systems being completed next week.
  • The majority of Linux distributions have already released their OS patches, but there are a few who we are still waiting on. We plan to address these patches in our next patch cycle at the beginning of February, so we can include all outstanding patches.
  • We are investigating the possibility of bringing the patch cycle forward, depending on the availability of the Linux patches.

 

=== Update 24/1/2018 ===

Our engineers have successfully applied all the relevant operating system patches across our Microsoft Windows servers. 
Linux servers are approximately 50% done, and completion will progress during the course of the week. 
Unfortunately hardware firmware updates are constantly being released and revoked due to stability issues they are presenting. 
As per recommendation from Intel, its advisable to not apply their current release. We subsequently took the decision to hold back on any firmware updates until the “fixes” have matured in stability.