HackAndPwn
Security & Vulnerability Researcher / Professional Penetration Tester

Windows 8.1 and Windows Server 2012 R2 ESU Analysis

The original Windows 7 ESU Analysis can be found here. With the ending of support for Windows 8.1 and Server 2012 R2 in 2023, additional research was conducted to see if similar techniques would work for these operating systems as well. It was determined that both Windows 8.1 and Windows Server 2012 R2 can be fully patched past the supported period.

There are 2 techniques in getting these Operating Systems up to date with the latest patches. The first technique is to copy the latest manifest file into the C:\Windows\WinSxS\Manifests folder, apply the Components registry key, and apply the SideBySide registry key. Then, installing the latest Cumulative Update will be successful.

The easier method, however, is to install the latest Cumulative Update, let it “fail”, apply the SideBySide registry key, and retry. Upon completion, the update will succeed. Both techniques have been validated on these Operating Systems.

Important: You must obtain an ESU license to apply ESU updates. Details on obtaining an ESU license can be found here. This research was completed for security vulnerability research purposes only following the Microsoft Legal Safe Harbor Terms. Do not try to reproduce without having the required licenses.

There is no ESU license option for Windows 8.1, so for security purposes if Windows 8.1 must still be used, this is an unsupported way on how to keep it patched against the latest vulnerabilities. Although the last official patch for Windows 8.1 was January 2023, here is a version of Windows 8.1 fully patched through January 2024.

Install The Latest Servicing Stack Update (SSU) - KB5037021 (April 2024)

Install Windows8.1-KB5037021-x64.msu and reboot the computer.

Install The Latest Monthly Cumulative Update Via Failed Reboot Technique - KB5037823 (May 2024)

  1. Install KB5037823 ( Part 1 / Part 2 / Part 3 / Part 4 / Part 5 / Part 6 ) and reboot the computer. This will result in a failed update and rollback.
  2. Apply the new Windows 8.1 or Server 2012 R2 SideBySide registry key linked below.
  3. Install KB5037823 again and reboot the computer. This will result in a successful update.

Install The Latest Monthly Cumulative Update Via Manifest/Component Technique - KB5037823 (May 2024)

If using the Manifest/Components registry key technique:

  1. Copy the manifest file linked below into the C:\Windows\WinSxS\Manifests folder. This can be done by executing the following commands:

    takeown /f C:\Windows\WinSxS\Manifests /a

    icacls C:\Windows\WinSxS\Manifests /grant Everyone:(F)

    copy amd64_microsoft-windows-s..edsecurityupdatesai_31bf3856ad364e35_6.3.9600.21972_none_599c7a4bf64e9ba1.manifest C:\Windows\WinSxS\Manifests

    icacls C:\Windows\WinSxS\Manifests /remove Everyone

    icacls C:\Windows\WinSxS\Manifests /setowner “NT SERVICE\TrustedInstaller”

  2. Apply the new Windows 8.1 or Server 2012 R2 Components registry key linked below.
  3. Apply the new Windows 8.1 or Server 2012 R2 SideBySide registry key linked below.
  4. Install KB5037823 ( Part 1 / Part 2 / Part 3 / Part 4 / Part 5 / Part 6 ).

Install The Latest .NET 3.5 Update - KB5036627 (April 2024)

Install Windows8.1-KB5036627-x64.msu.

Install The Latest .NET 4.8 Update - KB5037923 (May 2024)

Install Windows8.1-KB5037923-x64-ndp48.msu.

Install The Latest Root Certificate Updates

Finally, the latest Microsoft Root Certificates need to be installed into the Local Computer Trusted Root Authority Certificate Store. A batch file to automatically install all certificates and revocation lists can be found here: Import.cmd

DateTypeDownload
2018-08-02CertificateMicRooCerAut2011_2011_03_22.crt
2018-08-02CertificateMicrosoft ECC Product Root Certificate Authority 2018.crt
2018-08-02CertificateMicrosoft ECC TS Root Certificate Authority 2018.crt
2018-08-02CertificateMicrosoft Time Stamp Root Certificate Authority 2014.crt
2020-01-22CertificateMicrosoft ECC Root Certificate Authority 2017.crt
2020-01-22CertificateMicrosoft EV ECC Root Certificate Authority 2017.crt
2020-01-22CertificateMicrosoft RSA Root Certificate Authority 2017.crt
2020-01-22CertificateMicrosoft EV RSA Root Certificate Authority 2017.crt
2024-03-04Revocation ListMicRooCerAut_2010-06-23.crl
2024-03-12Revocation ListMicrosoft ECC Product Root Certificate Authority 2018.crl
2024-03-12Revocation ListMicrosoft ECC TS Root Certificate Authority 2018.crl
2024-03-21Revocation ListMicrosoft RSA Root Certificate Authority 2017.crl
2024-03-22Revocation ListMicrosoft EV ECC Root Certificate Authority 2017.crl
2024-03-22Revocation ListMicrosoft EV RSA Root Certificate Authority 2017.crl
2024-04-11Revocation ListMicrosoft Time Stamp Root Certificate Authority 2014.crl
2024-05-03Revocation ListMicrosoft ECC Root Certificate Authority 2017.crl

References

These files can all be found on GitHub here. See below for specific file links.

Windows 8.1 x64 Manifest File KB5037823

Windows 8.1 x64 Components Registry Key KB5037823

Windows 8.1 SideBySide Registry Key KB5037823

Windows Server 2012 R2 x64 Manifest File KB5037823

Windows Server 2012 R2 Components Registry Key KB5037823

Windows Server 2012 R2 SideBySide Registry Key KB5037823

Update 2024-05-16

  • Replaced April 2024 Monthly Update (KB5036960) with May 2024 Monthly Update (KB5037823).
  • Replaced April 2024 .NET Framework 4.8 Update (KB5036614) with May 2024 .NET Framework 4.8 Update (KB5037923).
  • Updated Microsoft ECC Root Certificate Authority 2017.crl.
  • Updated Microsoft Time Stamp Root Certificate Authority 2014.crl.
  • Replaced April 2024 Manifest, Components Registry Key, and SideBySide Registry Key (6.3.9600.21924) with May 2024 (6.3.9600.21972).

For previous updates to this post, see Windows 8.1 and Windows Server 2012 R2 ESU Analysis Changelog.


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