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Office 2010 & 2013 Clients End-of-Support Affecting Microsoft 365 GCC High Tenants and CMMC Impact.jpg

On November 1, 2021, Microsoft will no longer support Office 2010 & 2013 clients for Microsoft 365 Government Community Cloud (GCC) and Microsoft 365 GCC High tenants, and will deny access to Microsoft 365 GCC High. To ensure business continuity, reduce security risk, and maintain CMMC compliance, Summit 7 recommends assessing and planning your organizational upgrade today.


Primary Issue: Office desktop client applications, such as Outlook, OneDrive and Teams clients cannot connect to Microsoft 365 GCC High services. Windows Defender for Endpoint will also experience compatibility issues.


Microsoft Government Cloud Services are always evolving. New releases are iterated, tested, and released into the Microsoft Commercial Cloud and Government Community Cloud at a rapid cadence. After new applications and services have gone through the FedRAMP compliance certification, they are implemented in Office 365 GCC High. At the same time, aging versions of Microsoft Office and Windows desktop operating systems will face reliability and performance issues when connecting to the current release of Microsoft 365 Cloud platforms.


As of this writing, November is less than five months away. For most of our clients, the Microsoft End-of-Support for Office 2010 and Office 2013 falls in the next fiscal budget period to start planning and executing an organization migration for older devices, desktop OS, and Office applications. Additionally, the latest versions of Microsoft Office desktop applications come with the latest release of Windows 10 as an operating system requirement. Organizations can avoid future user experience issues by taking strategic steps now and increase proper cyber hygiene by updating out-of-support applications and OS. Even more, neglecting some of these steps may put your organization in a non-compliant state according to CMMC Level 3 requirements.


The CMMC Domain – System and Information Integrity (SI) – is one of the areas of concern when operating dated OS, firmware, and endpoint software. SI.1.210 for example requires organizations to “Identify, report, and correct information system flaws in a timely manner.” By keeping users on non-supported clients, the proper security updates will not occur, and the organization will be susceptible to advanced threats and jeopardize their ability to meet CMMC Level 3.


On the other hand, there can be a well planned approach to maintain certain workloads or end-of-life technologies. Risk Management (RM) 3.147 requires DIB suppliers to “Manage non-vendor supported products separately and restrict as necessary to reduce risk.” If a smaller user base needs to perform unique duties with Office 2010 or 2013 applications, the organization can consider isolating endpoints with firewalls or air-gapped network architectures.

Understanding Microsoft Fixed Policy Product Lifecycle

Microsoft Products are released in two phases generally covering a ten-year lifecycle —Mainstream Support and Extended Support.

  • Mainstream Support is the first phase of a product’s lifecycle and typically lasts five years. During this phase:

    • Microsoft receives requests and provides changes to product design and features

    • Performs security and non-security updates

    • Self-help and paid support options are available

  • Extended Support is the final phase of a product’s lifecycle and typically last five years from the end of the Mainstream Support. Microsoft only supports products at the published service level in Extended Support including:

    • Security updates

    • Paid programs

    • Unified Support customers have the ability to request non-security fixes for designated products

If it’s absolutely mission-critical to run legacy applications beyond the End of Support date, you typically can invest in Microsoft’ Extended Security Update (ESU) Program, but this is mostly untenable with Microsoft 365 GCC High.

Can I Delay Migrating Office 2010/2013?

Microsoft products are Secure by Design for the era the products were originally released and supported. Still, the cyber threat landscape is constantly evolving. As a result, older applications simply can’t keep pace with software innovation and effectively address software vulnerabilities. This particular flaw was on full display when organizations failed to patch and update Exchange 2013, resulting in the infamous SolarWinds attack. As we continue to see an escalation in the scale, scope, and sophistication of cyber threats in the United States from nation states and cyber criminals – the continued use of outdated applications, operating systems, and infrastructure is an open invitation for malicious actors to wreak havoc on your organization.

Final Thoughts for Migration Planning

Security and compliance are significant reasons on their own to migrate your organization to the latest clients for Windows and Microsoft 365 for your Government Cloud Services. More than that, there is another dynamic that is equally important—the productivity of your organization—in other words, the people dynamic.


Legacy Office applications are often customized for the organization’s mission and people. These customizations may use macros, scripts, addons, and third-party applications that are also out-of-support, no longer needed, or non-compliant with CMMC. Yet, people rely on these bespoke Office applications to perform their daily activities. Within the CMMC clarification documents, SC.3.180 explains “As legacy components in your architecture age, it may become increasingly difficult for those components to meet security principles and requirements. This should factor into life-cycle decisions…”


As you assess your inventory, be mindful to identify any customizations to your legacy Office applications. Some features may have been deprecated, replaced, or embedded into the latest versions of Microsoft 365. Note the changes so that you can prepare your people for what’s coming, what’s different, and how to enhance their productivity, collaboration, and mission-fulfillment.

Help Is Always Available

Getting a handle on the number of devices and their respective configurations can be a daunting task. Microsoft Endpoint Manager is a solution to assess and manage devices; as well as deploy apps across your organization’s desktops, laptops, tablets, and phones. It’s part of the Microsoft 365 Cloud and can help accelerate your organization’s ability to be compliant with regulations, mitigate cyber threats, and improve your organization’s productivity.


Microsoft keeps a short list of partners that understand the requirements for CMMC, Office 365 GCC High, and all of the nuance of modernizing DIB companies. You don’t have to tackle these challenges alone. Summit 7 can partner to help you assess your migration and start planning today, so that this year you can enjoy the holiday season in November/December.


Original Source Blog:

Brought to you by Dr. Ware, Microsoft Office 365 Silver Partner, Charleston SC.