This is a known vulnerability with publicised mitigation not some state-sponsored zero-day attack. I think this is all the evidence we need that many businesses just aren’t on top of patching. Time to turn on auto updates and accept the risk that vendor screw ups will occasionally take your servers down?…:
[…] But weeks later, many organisations are yet to apply the critical updates for Microsoft Exchange Server and cyber attackers are taking advantage to gain access to servers while it remains possible.
And cyber criminals are doing just that, with security researchers at F-Secure identifying tens of thousands of attacks targeting organisations around the world which are still running vulnerable Microsoft Exchange Server every day. According to F-Secure analytics, only about half of the Exchange servers visible on the internet have applied the Microsoft patches for these vulnerabilities.