On November 27, 2024, Microsoft re-released the November 2024 Security Updates (SUs) for Exchange Server to address issues identified in the initial release. The original update, released on November 12, 2024, caused transport rules to stop functioning after a certain period in some environments. The re-released update resolves this problem and introduces enhanced control over the X-MS-Exchange-P2FromRegexMatch header.
Key Differences Between SU Versions
- Nov 2024 SUv1: The original update (KB5044062) released on November 12, 2024.
- Nov 2024 SUv2: The re-released update (KB5049233) issued on November 27, 2024, which fixes the transport rules issue and provides more granular control for non-RFC compliant P2 FROM header detection.
Recommended Actions
- If SUv1 was installed manually and transport or DLP rules are not in use: It's recommended to install SUv2 to benefit from the enhanced header control.
- If SUv1 was installed via Microsoft/Windows Update without issues: The system will automatically download and install SUv2 in December 2024.
- If SUv1 was installed and later uninstalled due to transport rule issues: Install SUv2 to resolve the problem.
- If SUv1 was never installed: Proceed directly with the installation of SUv2.
For detailed guidance and download links, refer to the original November 2024 SU announcement. After installation, it's advisable to run the Exchange Health Checker to ensure all necessary steps are completed.
FAQs
- Is it necessary to install SUv2 if SUv1 was installed without issues?
Yes, installing SUv2 is recommended to gain enhanced control over specific header settings. - Will systems with SUv1 installed via automatic updates receive SUv2 automatically?
Yes, SUv2 will be available through automatic updates starting December 2024. - What are the specific changes in SUv2 compared to SUv1?
SUv2 resolves the transport rules issue present in SUv1 and offers improved control for non-RFC compliant P2 FROM header detection.
For comprehensive information, consult the original release blog post and the associated CVEs.
By promptly applying SUv2, organizations can maintain the security and functionality of their Exchange Server environments.
