[Updated] May Patch Tuesday updates are out with fix for new “ZombieLoad” CPU vulnerability

Laurent Giret

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Microsoft has just released new Patch Tuesday updates for all supported versions of Windows 10, including the May 2019 Update. All Windows Insiders running the build 18356.30 or later will get the build 18362.113 today, which includes a fix for a new critical vulnerability in modern processors called “ZombieLoad.”

Just like the previous Meltdown and Spectre CPU flaws, ZombieLoad represents a new subclass of speculative execution side-channel vulnerabilities. According to the researchers who discovered it, the ZombieLoad attack “resurrects your private browsing-history and other sensitive data. It allows to leak information from other applications, the operating system, virtual machines in the cloud and trusted execution environments.”

Techcrunch is reporting that Microsoft, Apple, Google and Mozilla are all releasing patches today to address this critical vulnerability. For Windows 10 users already running the May 2019 update, here are all the fixes included in the build 18362.113:

  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2018-11091, CVE-2018-12126CVE-2018-12127CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles(These registry settings are enabled by default for Windows Client OS editions and Windows Server OS editions).
  • Addresses an issue that decreases Internet Explorer’s performance when you use roaming profiles or you don’t use the Microsoft Compatibility List.
  • Addresses an issue that may cause the text, layout, or cell size to become narrower or wider than expected in Microsoft Excel when using the MS UI Gothic or MS PGothic fonts.

Be aware that after installing this patch, you may experience error “0x800705b4” when launching Windows Defender Application Guard or Windows Sandbox. Microsoft is working on a fix that will be available in an upcoming update.

The Patch Tuesday updates for older versions of Windows 10 all include the same fixes for the “ZombieLoad” CPU vulnerability. For users still running Windows 10 version 1809, the build 17763.503 will bring the following fixes:

  • Enables “Retpoline” by default if Spectre Variant 2 (CVE-2017-5715) is enabled. Make sure previous OS protections against the Spectre Variant 2 vulnerability are enabled using the registry settings described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions). For more information about “Retpoline”, see Mitigating Spectre variant 2 with Retpoline on Windows.
  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2018-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions and Windows Server OS editions).
  • Adds “uk.gov” into the HTTP Strict Transport Security Top Level Domains (HSTS TLD) for Internet Explorer and Microsoft Edge.
  • Addresses an issue that may cause “Error 1309” while installing or uninstalling certain types of .msi and .msp files on a virtual drive.
  • Addresses an issue that prevents the Microsoft Visual Studio Simulator from starting.
  • Addresses an issue that may cause zone transfers between primary and secondary DNS servers over the Transmission Control Protocol (TCP) to fail.
  • Addresses an issue that causes Simple Network Management Protocol (SNMP) Management Information Base registration to fail when the Windows Management Instrumentation (WMI) provider uses the Windows tool SMI2SMIR.exe.
  • Addresses an issue that may cause the text, layout, or cell size to become narrower or wider than expected in Microsoft Excel when using the MS UI Gothic or MS PGothic fonts.
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Graphics, Windows Storage and Filesystems, Windows Cryptography, the Microsoft JET Database Engine, Windows Kernel, Windows Virtualization, and Windows Server.

If you’re running the older version 1803 of Windows 10 (aka the April 2018 Update), the build 17134.765 is now available to download with the same ZombieLoad fixes and more. You can find the full list of improvements below:

  • Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 64-Bit (x64) versions of Windows (CVE-2018-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client and Windows Server articles. (These registry settings are enabled by default for Windows Client OS editions, but disabled by default for Windows Server OS editions).
  • Adds “uk.gov” into the HTTP Strict Transport Security Top Level Domains (HSTS TLD) for Internet Explorer and Microsoft Edge.
  • Addresses an issue that may cause “Error 1309” while installing or uninstalling certain types of .msi and .msp files on a virtual drive.
  • Addresses an issue that prevents the Microsoft Visual Studio Simulator from starting.
  • Addresses an issue that may cause zone transfers between primary and secondary DNS servers over the Transmission Control Protocol (TCP) to fail.
  • Addresses an issue that may cause the text, layout, or cell size to become narrower or wider than expected in Microsoft Excel when using the MS UI Gothic or MS PGothic fonts.
  • Security updates to Microsoft Edge, Internet Explorer, Microsoft Scripting Engine, Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Storage and Filesystems, Windows Cryptography, Windows Datacenter Networking, Windows Wireless Networking, Windows Virtualization, Windows Kernel, Windows Server, and the Microsoft JET Database Engine.

Microsoft also released new Patch Tuesday updates for Windows 10 versions 1709, 1703, 1607, and 1507, but all these updates are only available for Windows 10 Enterprise, Education, and IoT Enterprise edition. As usual, let us know in the comments if you encounter any issues after installing these new patches.

Update: In a blog post on the Microsoft Security Response Center, the company explained that older versions of Windows (expect Windows 8) are also affected by a critical Remote Code Execution vulnerability in Remote Desktop services. That’s why Microsoft is pushing today security updates for Windows 7, Windows Server 2008 R2, and Windows Server 2008, and the company is also doing the same for out-of-support versions such as Windows XP and Windows Server 2003. The software giant emphasized today that this Remote Code Execution vulnerability is “wormable,” but it hasn’t seen it being exploited by malicious actors so far.