Update Rollup 8 for Exchange Server 2007 SP3 resolves the issues that are described in the following Microsoft Knowledge Base articles:
2699574 Microsoft Exchange Information Store service may stop responding when you perform a search on Exchange mailboxes in an Exchange Server 2007 environment
2701037 Events 4999 and 7034 are logged and the Microsoft Exchange Information Store service crashes on an Exchange Server 2007 mailbox server
2730089 Microsoft Exchange Information Store service may stop responding when you perform a search on Exchange mailboxes in an Exchange Server 2007 environment
2732525 Outlook keeps prompting you for credentials and incorrectly connects to an out-of-site global catalog after you install Update Rollup 6 for Exchange Server 2007 SP3.
Update Rollup 8 for Exchange Server 2007 SP3 also resolves the issue that is described in Microsoft Security Bulletin MS12-058.
For more information about Security Bulletin MS12-058, click the following article number to view the article in the Microsoft Knowledge Base: 2740358 MS12-058: Vulnerability in Microsoft Exchange Server WebReady document viewing could allow remote code execution: August 14, 2012