Customers running Exchange Server 2007 RTM need to apply Update Rollup 7 for Exchange 2007 RTM to address the security issue.
Customers running Exchange Server 2007 SP1 need to apply Update Rollup 3 for Exchange 2007 SP1 to address the security issue.
Rollup installation troubleshootingSeeing that those Rollups contain security fixes, we expect that a lot of people will be applying them. There are a few possible issues that we would like you to be aware of:
During the installation of the Rollup, you might encounter a message that you have to wait until the disk space calculation is completed. This message will clear by itself and then you will be able to proceed further. We will permanently resolve this in the future.
When installing a Rollup, we recommend you use the same account that you used to install Exchange Server. If you are using a different account, that account needs to have Local Administrator rights as well as rights to read Active Directory on Exchange object as well as server level (as the update needs to determine which roles are installed on the server). Not having required permissions can lead to OWA not being updated correctly and displaying a blank page after update has completed.
If you have modified the logon.aspx file, it will not be patched by the Update Rollup installer. As a result Outlook Web Access may not be updated correctly and it may display a blank page after the update has finished. In order to avoid this problem, rename the logon.aspx file before applying the update rollup. After you apply an update rollup package, you must re-create Outlook Web Access customization in logon.aspx.