Copy both Exchange2013PatchCheck-ProxyLogon.ps1 and ExchangeFilePatchVersions.csv into a folder on the system to be scanned.
Run the script from a PowerShell prompt and review the output.
.\Exchange2013PatchCheck-ProxyLogon.ps1
File lists for other versions can be pulled from Microsoft's KB Article details page. https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-microsoft-exchange-server-2019-2016-and-2013-march-2-2021-kb5000871-9800a6bb-0a21-4ee7-b9da-fa85b3e1d23b