Update 4/23/2024: We have now released April 2024 Hotfix Updates which address known issues in March 2024 SU updates.
Microsoft has released Security Updates (SUs) for vulnerabilities found in:
...
Updated Apr 23, 2024
Version 8.0
Blog Post
> I'm no expert but it seems to me that you could hire somebody to write a transport plugin or route it >through a relay that > could strip the header containing the Exchange version information out entirely, so all this seems to be a >solution in search > of a problem to me, but what do I know.
You can stick a Cisco ASA in front of an Exchange server and it does this, that solution has already been written. But then of course you have to pay a subscription for that.
The problem is there could be buffer overflow in the SMTP transaction of some other issue in that old Exchange version no way to know. The attackers are not going care anyway if the handshake is obscured they will just throw all the known attacks at the server anyway. Security via obscurity is a bankrupt approach.