Note: this post is getting frequent updates; please keep checking back. Last update: 3/19/2021
Microsoft has released a set of out of band security updates for vulnerabilities for the following ver...
Updated Mar 19, 2021
Version 44.0
Blog Post
to_vaib: It sounds like you are not on the most recent CU for your Exchange server. For Exchange 2013 you need to be on CU23, so you probably need to update it to CU23 first. To see what version you are on you can run the HealthChecker.ps1 that is linked to in the blog post that all these comments are on, in the section:
How can I get an inventory of the update-level status of my on-premises Exchange servers?
You can use the Exchange Server Health Checker script, which can be downloaded from https://aka.ms/ExchangeHealthChecker (use the latest release). Running this script will tell you if you are behind on your on-premises Exchange Server updates (note that the script does not support Exchange Server 2010).