April 9, 2024-Security Only Update for .NET Framework 2.0, 3.0 for Windows Server 2008 SP2 (KB5036633)

Summary

CVE-2024-21409 - .NET Framework Remote Code Execution Vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2024-21409.

.NET Framework Defense in Depth Vulnerability
This security update addresses an issue where version of the OSS zlib library is out of date.

.NET Framework Defense in Depth Vulnerability
This security update addresses an issue in AIA fetching process.

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

• 5037128 Description of the Security Only Update for .NET Framework 2.0, 3.0, 3.5 SP1, 4.6.2 for Windows Server 2008 SP2 (KB5037128)

Known issues in this update

Microsoft is not currently aware of any issues in this update.

How to get this update

Before installing this update

Prerequisite:

To apply this update, you must have .NET Framework 2.0, 3.0 installed.

You must install the updates listed below and restart your device before installing the latest Rollup. Installing these updates improves the reliability of the update process and mitigates potential issues while installing the Rollup and applying Microsoft security fixes.

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.

Install this update

Restart requirement

You may need to restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update.

Update deployment information

For deployment details for this security update, see the Deployments tab of the Microsoft Security Response Center (MSRC) Security Update Guide.

Update replacement information

This update replaces previously released updates KB5034690 and KB5034280.

File Information

How to obtain help and support for this update

• Help for installing updates: Windows Update FAQ

• Protect yourself online and at home: Windows Security support

• Local support according to your country: International Support