Owa intergration broken since cumulative update 16 on Exchange 2016

[chrisland]

Hi All,

Anyone come across this issue before, running exchange 2016 cu update 12 with OWA integration. Since updating to cu16, owa no longer prompts for 2 factor auth just lets the user authenticate without duo prompt

Cheers

Chris

[chrisland · Accepted solution]

its ok i found it:

Duo Security

Duo for Outlook Web App (OWA) FAQ

Duo integrates with Microsoft Outlook Web App to add two-factor authentication to OWA logins. Read our FAQs on Outlook Web App to learn more.

Why did Duo stop working after I installed an Exchange Cumulative Update (CU)?

Installing Duo’s protection for OWA modifies some of Exchange’s XML application configuration files. Exchange 2010 and 2013 CU installers overwrite any customizations to the XML files (see Microsoft TechNet for details). Remove and reinstall the Duo application after the CU install is completed.

This issue with overwriting the XML configuration files during CU install was corrected in Exchange 2016 CU 1, but has been observed again in later cumulative updates. Therefore, we recommend always uninstalling Duo for OWA before applying any CU and reinstalling Duo for OWA after CU install success.