July 9, 2024-Security Only Update for .NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Server 2008 R2 SP1 and Windows Server 2008 SP2 (KB5040122)

Breaking change details

The .NET Framework servicing update released on July 2024 security and quality rollup - .NET Framework contains a security fix addressed an elevation of privilege vulnerability detailed in CVE 2024-38081. The fix changed System.IO.Path.GetTempPath method return value. If windows version exposes the GetTempPath2 Win32 API, this method invokes that API and returns the resolved path. See the Remarks section of the GetTempPath2 documentation for more information on how this resolution is performed, including how to control the return value through the use of environment variables. The GetTempPath2 API may not be available on all versions of Windows.

Please reference to the System.IO.Path.GetTempPath API for more information.

Temporary workaround

⚠️ Warning: The opt-out will disable the security fix for the elevation of privilege vulnerability detailed in CVE 2024-38081. The opt-out is only for temporary workaround if you're sure that the software is running in secure environments. Microsoft does not recommend applying this temporary workaround.

• Option#1: Opt out in a command window by setting the environment variable​​​​​​​

  • COMPlus_Disable_GetTempPath2=true

• Opiton#2: Opt out globally on the machine by creating a system-wide environment variable and rebooting to ensure all processes observe the change. ​​​​​​​​​​​​​​

  • System-wide environment variables can be set by running “sysdm.cpl” from a cmd window, and then navigating to “Advanced -> Environment variables -> System variables -> New”. 

Resolution

The API behavior change is by design to address the elevation of privilege vulnerability. Any affected software or application is expected to make code change to adapt to this new design change.

Windows Server 2008 SP2

1. The April 9, 2019 servicing stack update (SSU) (KB4493730). To get the standalone package for this SSU, search for it in the Microsoft Update Catalog. This update is required to install updates that are only SHA-2 signed.

2. The latest SHA-2 update (KB4474419) released October 8, 2019 or newer update. If you are using Windows Update, the latest SHA-2 update will be offered to you automatically. This update is required to install updates that are only SHA-2 signed. For more information on SHA-2 updates, see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.

3. To get this security update, you must reinstall the "Extended Security Updates (ESU) Licensing Preparation Package" (KB5016891) for Windows Server 2008 SP2 that is dated August 8, 2022 even if you previously installed the ESU key. The ESU licensing preparation package will be offered to you from WSUS. To get the standalone package for ESU licensing preparation package, search for it in the Microsoft Update Catalog.

4. After you install the items above, we strongly recommend that you install the latest SSU. For Windows Server 2008 SP2, you must have the servicing stack update (SSU) (KB5016129) that is dated July 12, 2022 or later installed. For more information about the latest SSU updates, see ADV990001 | Latest Servicing Stack Updates.
   
   If you use Windows Update, the latest SSU will be offered to you automatically if you are an ESU customer. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

5. Download the ESU MAK add-on key from the VLSC portal and deploy and activate the ESU MAK add-on key. If you use the Volume Activation Management Tool  (VAMT) to deploy and activate keys, follow the instructions here.

   IMPORTANT You do not need an additional key for deployment of the following:

   • You do not need to deploy an additional ESU key for Azure virtual machines (VMs), Azure Stack HCI, version 21H2 and later.

   • For other Azure products such as Azure VMWare, Azure Nutanix solution Azure Stack (Hub, Edge), or for bring-your-own images on Azure for Windows Server 2008 SP2, you do need to deploy the ESU key.  The steps to install, activate, and deploy ESUs are the same for the fourth year of ESU coverage.

Windows Server 2008 R2

1. The March 12, 2019 servicing stack update (SSU) (KB4490628). To get the standalone package for this SSU, search for it in the Microsoft Update Catalog. This update is required to install updates that are only SHA-2 signed.

2. The latest SHA-2 update (KB4474419) released September 10, 2019 or newer update. If you are using Windows Update, the latest SHA-2 update will be offered to you automatically. This update is required to install updates that are only SHA-2 signed. For more information on SHA-2 updates, see 2019 SHA-2 Code Signing Support requirement for Windows and WSUS.

3. To get this security update, you must reinstall the "Extended Security Updates (ESU) Licensing Preparation Package" (KB5016892) for Windows Server 2008 R2 SP1 that is dated August 8, 2022 even if you previously installed the ESU key. The ESU licensing preparation package will be offered to you from WSUS. To get the standalone package for ESU licensing preparation package, search for it in the Microsoft Update Catalog.

4. After you install the items above, we strongly recommend that you install the latest SSU.

   ​​​​​​​For Windows Server 2008 R2 SP1, you must have the servicing stack update (SSU) (KB5017397) that is dated September 13, 2022 or later installed. For more information about the latest SSU updates, see ADV990001 | Latest Servicing Stack Updates.
   
   If you use Windows Update, the latest SSU will be offered to you automatically if you are an ESU customer. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

5. Download the ESU MAK add-on key from the VLSC portal and deploy and activate the ESU MAK add-on key. If you use the Volume Activation Management Tool  (VAMT) to deploy and activate keys, follow the instructions here.

   IMPORTANT You do not need an additional key for deployment of the following:

   • You do not need to deploy an additional ESU key for Azure virtual machines (VMs), Azure Stack HCI.

   • For other Azure products such as Azure VMWare, Azure Nutanix solution Azure Stack (Hub, Edge), or for bring-your-own images on Azure for Windows Server 2008 SP2, and Windows Server 2008 R2 SP1 you do need to deploy the ESU key.  The steps to install, activate, and deploy ESUs are the same for the fourth year of ESU coverage.

Release Channel

Available

Next Step

Windows Update and Microsoft Update

No

See the other options below.

Microsoft Update Catalog

Yes

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Windows Server Update Services (WSUS)

Yes

This individual .NET Framework product update will be installed, as applicable, by applying the operating system update. For more information about operating system updates see additional information about this update section.