Microsoft: October Windows Server updates break Exchange sign-in, mail flow
Summary
Microsoft has confirmed that its October Windows Server security updates are causing problems with Outlook Web App (OWA) sign-in and mail delivery on some Exchange Server systems. The issues appear to be related to specific security updates for Windows Server.
IFF Assessment
This is bad news for defenders as it highlights a disruption caused by a security update, potentially impacting critical mail flow and access for users.
Defender Context
Defenders should be aware of potential disruptions following Windows Server and Exchange Server patching cycles. It is crucial to test updates in a staging environment before applying them to production to avoid unintended consequences like broken sign-in or mail flow. This incident underscores the importance of robust rollback plans and clear communication channels when applying security patches.