The new one-click Microsoft Exchange On-Premises Mitigation Tool is meant to serve as an interim mitigation for those that aren't familiar with the patching process or that haven't yet applied the Exchange security updates released on March 2, Microsoft explains in a blog post. The company last reported some 82,000 Exchange Servers remain vulnerable to the exploits. This is not a replacement for the Exchange Server security update, Microsoft says, but it is an efficient way to defend against the highest risks to Internet-connected, on-premises Exchange Servers for organizations that haven't yet applied the patch. The tool has been tested across Exchange Server 2013, 2016, and 2019, all of which are affected by the recently patched flaws.