Tag Archives: Intel

Vendors Respond to Spectre NG Vulnerabilities

On Monday more details of these vulnerabilities were made available by affected vendors among them Red Hat, Google, Intel, IBM and Microsoft. There are two new vulnerabilities named:

Rogue System Register Read (Spectre Variant 3a) (CVE-2018-3640)

Speculative Store Bypass (SSB) (Spectre Variant 4) (CVE-2018-3639)

Why should these vulnerabilities be considered important?

Rogue System Register Read cannot be leveraged by an external attacker; they must instead log onto a vulnerable system and carry out further steps to exploit it. Once exploited the attacker may be able to obtain sensitive information by reading system parameters via side-channel analysis.

For Windows; successful exploitation of this vulnerability will bypass Kernel Address Space Layout Randomization (KASLR) protections. I have talked about ASLR (defined) before but provides this link more detail on kernel ASLR.

Google Project Zero’s Jann Horn and Microsoft’s Ken Johnson first reported Speculative Store Bypass. It can possibly be used by attacker externally (from the internet). I use the term “possibly” since the mitigations added to web browsers following Spectre variant 2 earlier this year will make it more difficult for an attacker to do so. Indeed, Intel rates the risk as “moderate.” This is a more serious vulnerability which may allow an attacker access to read privileged memory areas. An example would be a script running in one browser tab being able to read data from another browser tab.

Red Hat have made available a video more clearly explaining the Speculative Store Bypass (SSB) vulnerability.

How can I protect myself from these vulnerabilities?
At this time microcode updates are being developed by Red Hat, AMD, ARM, Intel, IBM and Microsoft. The affected products from each vendor are available from the following links. These vulnerabilities will not be addressed via software fixes but hardware fixes instead.

It is recommended to follow the best practice advice for these vulnerabilities as per the US-CERT namely:

1. Please refer to and monitor the links below for the updates from affected vendors.
2. Test these updates before deploying them widely
3. Ensure the performance impact (anticipated to be between 2 – 8%) is acceptable for the systems you manage/use.

These updates will ship with the mitigations disabled and if appropriate/acceptable for an affected system; the protection (along with its performance impact) can be enabled.

These updates are scheduled to be made available before the end of May. Cloud vendors (e.g. Amazon AWS, Microsoft Azure etc.) will also update their systems once the performance impact is determined and if deemed acceptable.

Thank you.

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AMD:
https://www.amd.com/en/corporate/security-updates

ARM:
https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability

IBM:
https://www.ibm.com/blogs/psirt/potential-impact-processors-power-family/

Intel:
https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00115.html

Microsoft (full impact yet to be determined):
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV180012

https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/ADV180013

Red Hat:
https://access.redhat.com/security/cve/cve-2018-3639

VMware ESXI, Fusion/Fusion Pro, Workstation/Workstation Pro and vCenter Server:
https://www.vmware.com/security/advisories/VMSA-2018-0012.html

https://kb.vmware.com/s/article/54951

https://kb.vmware.com/s/article/55111
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Responding to the Meltdown and Spectre Vulnerabilities

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Please scroll down for more updates to this original post.
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Update: 23rd May 2018:
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For information on the Spectre NG vulnerabilities please refer to this new blog post

Thank you.

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Original Post:
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Earlier in January updates for Linux, Apple and Windows were made available to work towards addressing the 3 security vulnerabilities collectively known as Meltdown and Spectre.

Why should these vulnerabilities be considered important?
I’ll provide a brief summary of the two categories of vulnerabilities:

Meltdown (CVE-2017-5754): This is the name of the vulnerability discovered that when exploited by an attacker could allow an application running with standard privileges (not root or elevated privileges) to read memory only intended for access by the kernel.

Spectre (Variant 1: CVE-2017-5753 ; Variant 2: CVE-2017-5715): This is a category of two known vulnerabilities that erode the security boundaries that are present between applications running on a system. Exploitation can allow the gathering of information from applications which could include privileged information e.g. usernames, password and encryption keys etc. This issue can be exploited using a web browser (e.g. Apple Safari, Mozilla Firefox, Google Chrome, Microsoft Edge (or IE) by using it to record the current time at very short intervals. This would be used by an attacker to learn which memory addresses were cached (and which weren’t) allowing the attacker to read data from websites (violating the same-origin policy) or obtain data from the browser.

Browser vendors have responded by reducing the precision of JavaScript timing and making it more unpredictable while other aspects of JavaScript timing (using the SharedArrayBuffer feature) have been disabled.

More in-depth (while still being less technical) descriptions of these issues are available here , here and here.

How can I protect myself from these vulnerabilities?
Since these vulnerabilities are due to the fundamental architecture/design of modern CPUs; it is not possible to fully address them. Instead a combination of software fixes and microcode updates (defined) is more a viable alternative than re-designing the established architecture of modern CPUs.

In-depth lists of updates available from multiple vendors are available here and here. I would suggest glancing at the affected vendors and if you own a device/product from them; checking if you are affected by these vulnerabilities. A list of BIOS (defined) updates from multiple vendors are available here. Google Chrome has a Site Isolation mode that can mitigate these vulnerabilities which will be more comprehensively addressed in Chrome version 64 scheduled for release last this month.

At this time my systems required updates from Google, Mozilla, Microsoft, Apple, VMware, Asus, Lenovo and Nvidia. Many of many existing desktops are unlikely to receive microcode and BIOS updates due to be more than 3 years old. However my Windows 10 laptop has received a BIOS update from the manufacturer.

Are there disadvantages to installing these updates?
While these updates increase security against these vulnerabilities; performance issues and stability issues (Intel and AMD) after the installation of these updates have been reported. These vary in severity but according to Intel and Microsoft the updates will be refined/optimised over time.

Benchmarks (for desktops) made available by TechSpot show negligible impact on most tasks that would stress a CPU (defined). However any work that you perform which makes of large files e.g. databases may be significantly impacted by the performance impact these updates have when accessing files on disk (mechanical and solid state). For laptops the slowdown was felt across almost all workload types. Newer and older silicon were inconsistently impacted. At times even some Intel 8th generation CPUs were impacted more than 5th generation CPUs.

Details of the anticipated performance impact for Linux, Apple macOS (and iOS) and Windows are linked to. Further reports of reduced performance from Intel and Apple devices have also been recorded. Further details of a feature known as PCID (Process-Context Identifiers) within more recent CPUs which will help reduce the performance impact are provided here. For Intel CPUs, 4th generation Core CPUs and later should include it but any CPU manufactured after 2011 should have it (one of my CPUs; a Core i7 2600K has this feature, verified using Sysinternals Coreinfo). A full list of Intel CPUs affected by these vulnerabilities is here.

Conclusion:
With the widely reported stability and performance issues present it is your decision if you install the necessary updates now or wait until further refinements. If you experience issues, please report them to the manufacturers where possible and within online forums if not. More refined updates will only be created if a need to do so is established.

I’m in the process of updating my systems but will benchmark them before and after each updates to determine an impact and make a longer term decision to keep the updates or uninstall them until further versions become available. I’ll update this post as I gather more results.

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Update: 16th January 2018:
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A newly released free utility from Gibson Research (the same website/author as the well-known ShieldsUp firewall tester) named InSpectre can check if your Windows system has been patched against Meltdown and Spectre and can give an indication of how much the performance of your system will be affected by installing and enabling the Windows and/or the BIOS updates.

Please note: I haven’t tried this utility yet but will this weekend (it will help with the tests I’m carrying out (mentioned above). I’ll update this post when I have tried out this utility.

Thanks again.

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Update: 24th January 2018:
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As promised I gathered some early results from a selection of CPUs and the results for all but recent CPUs are evidence they will experience a potentially noticeable performance drop:

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CPUs supporting PCID (obtained using Sysinternals Coreinfo):
Intel Core i7 Extreme 980X @ 3.33 GHz
Intel Core i7 2600K @ 3.8 GHz
Intel Core i5 4590T @ 3.3 GHz
Intel Core i7 6500U (laptop CPU) @ 2.5 GHZ

CPUs supporting INVPCID (obtained using Sysinternals Coreinfo):
Intel Core i5 4590T @ 3.3 GHz
Intel Core i7 6500U (laptop CPU) @ 2.5 GHZ
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Explanations of the purpose and relevance of the PCID and INVPCID CPU instructions are available from this Ars Technica article. The results from InSpectre only show positive results when both PCID and INVPCID are present backing up the observations within the above linked to Ars Technica article (that the updates take advantage of the performance advantages of these instructions when both are present).

The results from InSpectre back up these findings by stating that the 980X and 2600K will not deliver high performance protection from Meltdown or Spectre. Since my PCs are mainly used for more CPU intensive tasks (rather than disk intensive) e.g. games and Folding@Home; I still don’t expect too much of a performance decrease. The older CPUs are due for replacement.

You may ask; “why am I so concerned with the performance impact of these updates?” The answer is that significant time and investment has been made into the above systems for them to perform at peak performance for the intended tasks I use them for. Performance and security are both very important to me and I believe there should only be a small trade off in performance for better security.

My next step will be to benchmark the CPU, hard disk and GPU of each system before and after installing each update. I will initially do this for the 6500U and 2600K systems and provide these results. The categories of updates are listed below. I will keep you informed of my findings.

Thank you.
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Update 1: Software updates from Microsoft for Meltdown and Spectre
Update 2: Firmware update (where available)
Update 3: Nvidia / AMD GPU driver update
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Update: 13th February 2018:
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Sorry for the long delay (I was travelling again for my work). The above benchmarking is now taking place and I will make the results available as soon as possible. Thanks for your understanding.

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Update: 27th February 2018
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Earlier last week Intel made available further microcode updates for more CPUs. These updates seek to address variant 2 of the Spectre vulnerability (CVE-2017-5715). Updates are now available for the CPUs listed below.

As before, please refer to the manufacturer of your motherboard of your system for servers, desktops and laptops or the motherboard manufacturer for any custom built systems you may have to determine if these updates have been made available for your specific systems. Further information for corporate system administrators containing details of the patching process is available within this link (PDF):

  • Kaby Lake (Intel 7th Generation Core CPUs)
  • Coffee Lake (Intel 8th Generation Core CPUs)
  • Further Skylake CPUs (Intel 6th Generation Core CPUs)
  • Intel Core X series (Intel Core i9 CPUs e.g. in the 7900 and 7800 model range)
  • Intel Xeon Scalable (primarily targeted at data centres)
  • Intel Xeon D (primarily targeted at data centres)

Information on patches now available for OpenBSD and FreeBSD are located within the following links:

OpenBSD:
OpenBSD mailing list
The Register: OpenBSD Patch now Available

FreeBSD:
FreeBSD Wiki
Softpedia: Spectre and Meltdown mitigations now available

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Update: 1st April 2018
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As vendors have responded to these vulnerabilities; updates have been released for many products. I will describe these updates in more detail below. Apologies if I have omitted any, this isn’t intentional but the list below should still be useful to you:

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Google ChromeOS:
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Following the release of ChromeOS 64 in February which provided updates against the Meltdown and Spectre vulnerabilities, ChromeOS 65 includes further mitigations against these vulnerabilities including the more efficient Retpoline mitigation for Spectre variant 2.

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Sony Xperia:
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In late February Sony made available updates which include mitigations for Meltdown and Spectre for their Xperia X and Xperia X Compact phones which brings the build number to 34.4.A.2.19

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Microsoft Issues Microcode Updates:
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As previously mentioned when this blog post was first published; updates for the Meltdown and Spectre vulnerabilities are made up of software updates, microcode updates and firmware (BIOS updates) and GPU drivers.

Due to the complexity of updating the firmware of computer systems which is very specific and potentially error prone (if you apply the wrong update to your device it can render it useless, meaning it will need to be repaired/replaced (which is not always possible) Microsoft in early March began to issue microcode driver updates (as VMware describes they can be used as substitutes for firmware updates). Microcode updates have been issued in the past to address CPU reliability issues when used with Windows.

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Intel Firmware Updates:
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As with previous microcode updates issued by Intel in late February; these updates seek to resolve variant 2 of the Spectre vulnerability (CVE-2017-5715).

While Intel has issued these updates; they will be made available separately by the manufacturer of your motherboard of your system for servers, desktops and laptops or the motherboard manufacturer for any custom built systems you may have. You will have to determine from the updates those vendors issue if they are available for the products that you own.

Unfortunately not all systems will receive these updates e.g. most recent system was assembled in 2014 and has not received any updates from the vendor; the vendor has issued updates on their more recent motherboards. Only my 2016 laptop was updated. This means that for me; replacing the systems gradually is the only means of addressing variant 2 of the Spectre vulnerability.

Intel’s updates are for the Broadwell (5th generation CPUs i.e. 5000 series) and Haswell (4th generation CPUs i.e. 4000 series).

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Microsoft Surface Pro:
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Earlier this week Microsoft released firmware updates for their Surface Pro which mitigate the Meltdown and Spectre vulnerabilities. This link provides further details and how to install the updates.

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Microsoft Issues Further Security Update on the 29th March:
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As noted in my separate post; please refer to that post for details of a security update for Windows 7 SP1 64 bit and Windows Server 2008 R2 SP1 64 bit that resolve a regression (an un-intentional coding error resulting in a previously working software feature no longer working, alternative definition here) which introduced an additional elevation of privilege (defined) security vulnerability in the kernel (defined) of those Windows versions.

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Microsoft Offers Bug Bounty for Meltdown and Spectre vulnerabilities:
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Microsoft have announced bug bounties from $5000 to $250,000 to security researchers who can locate and provide details of exploits for these vulnerabilities upon Windows, Azure and Microsoft Edge.

If such a programme is successful it could prevent another instance of needing to patch further related vulnerabilities after the issues have been publicly disclosed (defined). This is sure to assist the system administrators of large organisations who currently in the process of deploying the existing updates or who may be testing systems on a phased basis to ensure performance is not compromised too much.

Further details are available from this link.

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Update: 6th April 2018
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Earlier this week, Intel issued a further progress update for the deployment of further microcode for their CPUs.

A further 5 families of CPUs have now completed testing and microcode updates are available. These families are:

    • Arrandale
    • Clarkdale
    • Lynnfield
    • Nehalem
    • Westmere

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However a further 9 families will not receive such updates for the reasons listed below. Those families are:

      • Micro-architectural characteristics that preclude a practical implementation of features mitigating [Spectre] Variant 2 (CVE-2017-5715)
      • Limited Commercially Available System Software support
      • Based on customer inputs, most of these products are implemented as “closed systems” and therefore are expected to have a lower likelihood of exposure to these vulnerabilities.

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      • Bloomfield
      • Clarksfield
      • Gulftown
      • Harpertown Xeon
      • Jasper Forest
      • Penryn
      • SoFIA 3GR
      • Wolfdale
      • Yorkfield

This announcement from Intel means my Intel Core i7 Extreme 980X (from 2010) won’t receive an update. This system isn’t used very much on the internet and so the impact is limited. I am hoping to replace this system in the near future too.

Recommendations:

Please review the updated PDF made available by Intel (I can upload the PDF to this blog if Intel place it behind an account which requires sign in. At this time the PDF link still works).

As before; please monitor the websites for the manufacturer of your system for servers, desktops and laptops or the motherboard manufacturer for any custom built systems you may have to determine if these updates have been made available for your specific systems.

Thank you.

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BranchScope Vulnerability Disclosed:
In a related story; four security researchers from different universities responsibly disclosed (defined) a new side channel attack affecting Intel CPUs. This attack has the potential to obtain sensitive information from vulnerable systems (a similar result from the existing Meltdown and Spectre vulnerabilities).

Further details of this attack named “BranchScope” are available in this Softpedia article and this paper from the researchers. Within the above article Intel responded to this attack stating that this vulnerability is similar to known side channel and existing software mitigations (defined) are effective against this vulnerability. Their precise wording is provided below.

Thank you.

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An Intel spokesperson has provided the following statement:

“We have been working with these researchers and have determined the method they describe is similar to previously known side channel exploits. We anticipate that existing software mitigations for previously known side channel exploits, such as the use of side channel resistant cryptography, will be similarly effective against the method described in this paper. We believe close partnership with the research community is one of the best ways to protect customers and their data, and we are appreciative of the work from these researchers.”
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Update: 13th April 2018
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AMD have issued microcode (defined) updates for Windows 10 Version 1709 to enhance the protection of their customer’s against variant 2 (CVE-2017-5715) of the Spectre vulnerability. Further details of these updates are available within these KB articles: KB4093112 and KB3073119

Thank you.

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Update: 18th May 2018
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Please refer to the beginning of the May and April security update summaries for further updates related to addressing Spectre variant 2 (v2).

 

WPA2 KRACK Vulnerability: What you need to know

Last Sunday, the early signs of a vulnerability disclosure affecting the extensively used Wi-Fi protected access (WPA2) protocol were evident. The next day, disclosure of the vulnerability lead to more details. The vulnerability was discovered by  two researchers Mathy Vanhoef and Frank Piessens of the Katholieke Universiteit Leuven (KU Leuven) while examining OpenBSD’s implementation of the WPA2 four way handshake.

Why should this vulnerability be considered important?
On Monday 16th October, the KRACK (key re-installation attacks) vulnerability was disclosed. This vulnerability was found within the implementation of the WPA2 protocol rather than any single device making it’s impact much more widespread. For example, vulnerable devices include Windows, OpenBSD (if not already patched against it), Linux, Apple iOS, Apple macOS and Google Android.

If exploited this vulnerability could allow decryption, packet replay, TCP connection hijacking and if WPA-TKIP (defined) or GCMP (explained) are used; the attacker can inject packets (defined) into a victim’s data, forging web traffic.

How can an attacker exploit this vulnerability?
To exploit the vulnerability an attacker must be within range of a vulnerable Wi-Fi network in order to perform a man in the middle attack (MiTM)(defined). This means that this vulnerability cannot be exploited over the Internet.

This vulnerability occurs since the initial four way handshake is used to generate a strong and unique key to encrypt the traffic between wireless devices. A handshake is used to authenticate two entities (in this example a wireless router and a wireless device wishing to connect to it) and to establish the a new key used to communicate.

The attacker needs to manipulate the key exchange (described below) by replaying cryptographic handshake messages (which blocks the message reaching the client device) causing it to be re-sent during the third step of the four way handshake. This is allowed since wireless communication is not 100% reliable e.g. a data packet could be lost or dropped and the router will re-send the third part of the handshake. This is allowed to occur multiple times if necessary. Each time the handshake is re-sent the attacker can use it to gather how cryptographic nonces (defined here and here) are created (since replay counters and nonces are reset) and use this to undermine the entire encryption scheme.

How can I protect myself from this vulnerability?
AS described in this CERT knowledge base article.; updates from vendors will be released in the coming days and weeks. Apple (currently a beta update) and Microsoft already have updates available. OpenBSD also resolved this issue before the disclosure this week.

Microsoft within the information they published for the vulnerability discusses how when a Windows device enters a low power state the vulnerable functionality of the wireless connection is passed to the underlying Wi-Fi hardware. For this reason they recommend contacting the vendor of that Wi-Fi hardware to request updated drivers (defined).

Links to affected hardware vendors are available from this ICASI Multi-Vendor Vulnerability Disclosure statement. Intel’ security advisory with relevant driver updates is here. The wireless vendor, Edimax also posted a statement with further updates to follow. A detailed but easy to use list of many vendors responses is here. Since I use an Asus router, the best response I could locate is here.

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Update: 21st October 2017:
Cisco have published a security advisory relating to the KRACK vulnerability for its wireless products. At the time of writing no patches were available but the advisory does contain a workaround for some of the affected products.
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The above updates are software fixes but updates will also be made available for devices in the form of firmware updates e.g. for wireless routers, smartphones and Internet of Things (IoT)(defined) devices. For any wireless devices you own, please check with the manufacturer/vendor for available updates with the above CERT article and vendor response list detailing many of the common vendors.

Thank you.

Intel works with system vendors to address AMT vulnerability

In early May, Intel began the process of making available updates to resolve 2 critical security vulnerabilities within the hardware of corporate Intel systems. Security researchers located vulnerabilities within the co-processor which has the role of a management engine and to provide further features as part of Intel’s vPro technology. vPro allows IT teams to remotely administer systems (e.g. determine a systems status regardless of its condition, power on/power off, restart etc.) and provides capabilities including secure wiping of data should the device be lost or stolen.

Why should these vulnerabilities be considered important?
As documented within Intel’s advisory: The first vulnerability allows a remote attacker to gain system level privileges (the highest privileges available)(defined) thus allowing them to make any changes they wish to the affected system. This applies to systems with Intel Active Management Technology (AMT) or Intel® Standard Manageability (ISM) enabled.

The second vulnerability allows an attacker already located within your internal/corporate network to gain network or local system privileges on affected systems. This vulnerability affects AMT and systems with Intel Small Business Technology (SBT) enabled. Definitions for AMT, ISM and SBT are available from Intel. A useful FAQ on the vulnerabilities is available here.

Vulnerable systems are very likely to be in use by many corporate organisations and small businesses. The version numbers of the affected Intel technologies are listed within US-CERTs advisory. All Intel systems which have Intel Active Management Technology (AMT), Intel® Standard Manageability (ISM), and Intel® Small Business Technology enabled are vulnerable. Such systems have been in production for more than nine years.

It should be noted that only business configured devices have such enablement capabilities, the same vulnerabilities do not exist on consumer devices.  However, given the increasingly blurry distinction between user and business devices, especially with concepts such as Bring your own device (BYOD)(defined) these issues can easily be widespread and will take time to address. Intel has published steps which will help to identify affected systems.  A tool is also available from Intel’s download center.

For this vulnerability to be successfully exploited the Active Management Technology (AMT) must be configured to support remote administration.  This tool is not configured by default.

Moreover while the above mentioned three management technologies are vulnerable, the first vulnerability can only be exploited if Active Management Technology (AMT) is provisioned. If not provisioned, the second vulnerability applies.

These vulnerabilities are particularly severe since the management engine co-processor (mentioned above) can access any memory region within an affected system without the primary Intel processor (CPU)(defined) being aware of it. The co-processor can send, receive, read/write data travelling on your network below the level at which firewalls operate thus bypassing them. The management engine can also read and write to the systems storage device (a hard drive) upon the successful authorisation of a user. The co-processor also has read and write access to the devices screen (your monitor) all while remaining undetected and unlogged (events are not captured within the logs of your operating systems making detection by SIEMs (defined) unviable).

How can I protect myself from these vulnerabilities?
Intel has created a list of affected vendors which links to their respective websites including the status of the availability of updates as well as already completed/available updates.

While the preparation of updates is in progress, the following mitigation options are available:

  1. Un-provisioning Intel manageability SKU (stock keeping unit) clients to mitigate unprivileged network attacker from gaining system privileges (Unprovisioning Tool v1.0)
  2. Disabling or removing the Local Manageability Service (LMS) to mitigate unprivileged local attacker from gaining system privileges
  3. Optionally configuring local manageability configuration restrictions

Unfortunately it will take time for vendors to issue updates for all affected systems. If you are in any doubt if your systems are affected, please contact them. In addition, please continue to access the list of vendor websites (provided above) to monitor when the updates to your systems become available. If due dates are instead present at this time, you can schedule a downtime window for these systems to be updated.

Thank you.

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Aside:
What is a stock keeping unit (SKU)?

It refers to a specific item stored to a specific location. The SKU is intended as the most disaggregated level when dealing with inventory (Source)
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