Update Rollup 21 for Exchange 2007 Service Pack 3 is now available for direct download. Note that mainstream support for Exchange 2007 has already ended.
This is a security update and resolves a vulnerability that could allow an Elevation of Privilege in Oracle products installed on a Microsoft Exchange Server which are a part of Outlook Web App (OWA).
View: Description of Update Rollup 21 for Exchange Server 2007 Service Pack 3
View: Microsoft Security Bulletin MS16-108
Download: Update Rollup 21 for Exchange Server 2007 Service Pack 3 (KB3184711)
