MS16-004: Description of the security update for Office 2013: January 12, 2016

This security update resolves vulnerabilities in Microsoft Office that could allow remote code execution if a user opens a specially crafted Microsoft Office file. To learn more about these vulnerabilities, see Microsoft Security Bulletin MS16-004.

Note To apply this security update, you must have the release version of Service Pack 1 for Office 2013 installed on the computer.

For a complete list of affected versions of Microsoft Office software, see Microsoft Knowledge Base article 3124585.

Improvements and fixes

This update also contains fixes for the following nonsecurity issues:

• After you use the Office deployment tool to install Office 2013 Click-to-Run editions that have multiple language packs, the language that is set in the config.xml as the first language isn't set as the default language.
  
• After you save an Excel workbook that contains an unregistered ActiveX control in Excel 2013, Excel 2013 may crash.
  
• When you try to open a file that's encrypted by a custom encryption provider in an Office 2013 application, the application may crash.
  
• Assume that you delete a cell comment of a cell that has a fill effect in a workbook in Excel 2013. Then, you save the workbook. When you reopen the file, you receive the following error message:
  Excel found unreadable content in 'workbookname.xlsx'. Do you want to recover the contents of this workbook? If you trust the source of this workbook, click Yes.
  After you select the Yes button, you receive the following error message:
  Excel was able to open the file by repairing or removing the unreadable content.
• After you install the November 10, 2015 update for Office 2013 (KB3101360) or the December 8, 2015 update for Office 2013 (KB3114333), Office applications may hang or crash. This can affect one or more Office applications, such as Outlook 2013, Word 2013, Excel 2013, OneNote 2013, and PowerPoint 2013.