IMPORTANT Some customers who use Windows Server 2008 R2 SP1 and have activated their ESU multiple activation key (MAK) add-on before installing the January 14, 2020 updates might need to re-activate their key. Re-activation on the affected devices should only be required once. For information on activation, see this blog post.

重要说明 对于某些使用 Windows Server 2008 R2 SP1，并在安装 2020 年 1 月 14 日更新前已激活其 ESU 多激活密钥 (MAK) 加载项的客户，可能需要重新激活其密钥。 只需要在受影响的设备上重新激活一次。 有关激活的信息，请参阅此博客文章。

How to obtain and install the update Method 1: Windows Update. This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically.

How to obtain and install the update. Before installing this update. Prerequisite: To apply this update, you must have .NET Framework 4.5.2 installed.

Enhanced Key Usage (EKU) is described in RFC 5280 in section 4.2.1.12: This extension indicates one or more purposes for which the certified public key may be used, in addition to or in place of the basic purposes that are indicated in the key usage extension.For example, a certificate that’s used for the authentication of a client to a server must be configured for Client Authentication.

View products that this article applies to. Introduction. This August 2017 Update for Windows Server 2008 Service Pack 2 (SP2), Windows 7 Service Pack 1 (SP1) and Windows Server 2008 R2 SP1 includes cumulative reliability improvements in the .NET Framework 4.5.2.

Summary. This security update resolves vulnerabilities in Microsoft .NET Framework that could allow the following: A Remote Code Execution vulnerability in .NET Framework software if the software does not check the source markup of a file.

Additional information about this security update. For more information about this security update as it relates to Windows 7 Service Pack 1 (SP1) and Windows Server 2008 R2 SP1, see the following article in the Microsoft Knowledge Base:

Summary. Denial of service vulnerabilities exist when .NET Framework incorrectly handles objects in heap memory, or when .NET Framework and .NET Core incorrectly process RegEx strings.

Resolves a vulnerability in the Microsoft .NET Framework that could allow remote code execution when the .NET Framework fails to properly validate input before loading libraries. An attacker who successfully exploits this vulnerability could take control of an affected system. The attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.