Microsoft Exchange Servers to the latest Cumulative Updates is highly critical. It helps keep your on-premises Exchange Servers ready for the next emergency security updates released by Microsoft to patch vulnerabilities.
If your server is not running a supported Cumulative Update, it is ineligible for the security updates and remains vulnerable to malicious attacks. With increasing attacks on on-premises Exchange Servers, it’s now more important than ever to keep your servers updated to the latest Cumulative and Security updates.
Microsoft released the Cumulative Update 23 (CU23) for Exchange Server 2013 on May 3, 2021. The latest Cumulative Update 23 contains all security updates released before May 2021 and is eligible to receive newer security updates and patches.
Thus, if your organization is running an older Exchange Server 2013 CU, it is highly recommended to update to CU23 to continue receiving the latest hotfixes and stay protected against malicious attacks.
In this post, you will learn the step-by-step process to upgrade Exchange Server 2013 to Cumulative Update 23 and install the latest Security Updates.
Follow these steps to install CU23 for Exchange Server 2013.
Caution: Backup Exchange customizations, such as IIS settings, custom registry entries, and Outlook on the web (OWA) customizations (if any) as installing CU may overwrite or remove them.
Make sure to choose your language before downloading the CU.
Use /PrepareAD to update and prepare the Active Directory forest on your Exchange Server 2013 for CU23. It is also recommended that you extend schema by using the /PrepareSchema if the system is a member of the same Active Directory.
The steps are as follows:
.\Exchange2013-x64-cu23.exe /IAcceptExchangeServerLicenseTerms_DiagnosticDataON /PrepareSchema
.\Exchange2013-x64-cu23.exe /IAcceptExchangeServerLicenseTerms_DiagnosticDataON /PrepareAD /OrganizationName:"<Organization name>"
Once done, move to the next step.
To apply CU23 on your Exchange Server 2013, you must put the server in maintenance mode. The detailed steps are as follows:
Set-ServerComponentState -Identity “ExchangeServerName” -Component HubTransport -State Draining -Requester Maintenance
Set-ServerComponentState "ExchangeServerName" -Component ServerWideOffline -State Inactive -Requester Maintenance
Get-ServerComponentState -Identity "ExchangeServerName”
Then right-click on the .NET framework.exe file and choose Run as administrator.
Once installed, re-enable the services you stooped but do not start them.
You can now reboot the server.
To upgrade Exchange Server 2013 RTM or later edition to CU23, right-click on the Exchange2013-x64-cu23.exe file and choose Run as administrator.
Then follow the wizard to install the CU23 update.
You may also run the Setup.exe in unattended mode to install CU23 on Exchange Server 2013 using an elevated Command Prompt.
.\Exchange2013-x64-cu23.exe /IAcceptExchangeServerLicenseTerms_DiagnosticDataON /m:upgrade
After the CU23 update is applied, restart the server and reimport your saved customizations.
After the successful upgrade to Exchange Server 2013 CU23, you can switch off the maintenance mode by using the following commands:
Set-ServerComponentState “ExchangeServerName” –Component ServerWideOffline –State Active –Requester Maintenance
Set-ServerComponentState “ExchangeServerName” –Component HubTransport –State Active –Requester Maintenance
Execute the following command to verify that the server is not in maintenance mode.
Get-ServerComponentState –Identity “ExchangeServerName”
If the output displays ‘Active‘ Component status, it’s out of the maintenance mode. However, if any component is still inactive, you can activate it using the following command:
Set-ServerComponentState “ExchangeServerName” –Component “ComponentName” –State Active –Requester Maintenance
Once done, reboot the Exchange Server 2013.
Finally, you can install the latest Security Updates released by Microsoft for Exchange Server 2013 CU23 and patch the vulnerabilities.
The latest Security Update available at the time of writing this blog was released in January 2022. First, download the Security Update (KB5008631) for Exchange Server 2013 CU23 and then follow these steps to install it.
You must restart the Exchange Server after applying the Security Updates.
To check if the Exchange Server is successfully upgraded to CU23, open EMS and execute the following command to check the Exchange Server 2019 build number. If it shows Version 15.0 (Build 15.00), it means the server is successfully updated to CU23.
Get-ExchangeServer | fl Name,Edition,AdminDisplayVersion
To check if the January 2022 Security Update is applied, open Control Panel, go to Programs > Programs and Features, and click View installed updates.
You are now aware of the importance of updating the Exchange Server to the latest Cumulative Update and the process to upgrade your Exchange Server 2013 to the latest CU23 (at the time of writing this blog). However, if the installation fails or you encounter issues after the upgrade, refer to repair failed installations of Exchange Cumulative and Security updates to troubleshoot and fix the problem.
But if the problem is not fixed, your Exchange Server may become unusable. In such a case, use backup to set up a new server and restore the mailboxes. You may also use Exchange recovery software, such as Stellar Repair for Exchange, to recover mailboxes from failed Exchange Server database and then export them directly to the new Exchange Server. It also helps repair and extracts mailboxes from corrupt or damaged Exchange databases to PST.
Ravi Singh is a Senior Writer at Stellar®. He is an expert Tech Explainer, IoT enthusiast, and a passionate nerd with over 6 years of experience in technical writing. He writes about Data Recovery, File Repair, Email Migration, Linux, Windows, Mac, and DIY Tech. Ravi spends most of his weekends working with IoT devices and playing games on the Xbox. He is also a solo traveler who loves hiking and exploring new trails.