Released: March 2024 Exchange Server Security Updates

embert2165 and anyone else wondering why "Microsoft does not suggest uninstalling SUs when issues are found":

Security updates are problematic as far as rollback is concerned. Consider that in this month's release, there were no 0-day exploits. When we (or any other software vendor, for that matter) announce a fix for a specific vulnerability, this also kicks off the arms race where threat actors now know where to look for the unpatched vulnerability, as then they know where to look exactly and try figure out how to exploit the vulnerability to (possibly) deliver payload on unpatched servers.

This is why we will never recommend uninstalling updates. Once updates are released, the cat is out of the bag so to speak. Unlike a feature update, where rolling back would simply make a feature that you did not use until now anyway go away, you can't make threat actors unsee the vulnerability.

There is no question that ideally, we would not have regressions in security updates. We do a lot of work on this. But until we have a fix, we will provide workarounds, when available (as we did in this case). We are still working on updates that will address known issues in March 2024 SUs.