MicrosoftThanks for publishing the information. We are currently testing the update and will post findings here.
Update: We implemented the update on our managed environments and it all looks good (2019CU11 / 2016 CU22 and 2013CU23 - organizations including some hybrid and full on-prem DAGs). Currently we're finalizing some post installation "administative" (paperwork) tasks. The only thing is that during the installation process the HealthChecker.PS1 has been updated by MS although we downloaded the most recent version just before installing the SUs (Note: we always Run this script post installation as additional routine check).
Update 2 (march 17th): Today, we received an issue that in one of our environments (EXCH2019) attachments downloads doesn't work anymore in OWA. We run also other environments with various versions of Exchange and somehow one specific one has the issue. The others run also 2019, as wel 2016 and some 2013. We're not the only one with this issue > including my reply: https://techcommunity.microsoft.com/t5/exchange/owa-attachments-after-cve/m-p/3254283. Also our test 2019 environment doesn't have this issue. We did not notice this issue in any environment during update, unless we missed something.
Work-around > Temporary disable the CVE2021-1730 mitigations (Download Domains config). I will perform additional tests and troubleshoot later.
