This update resolves vulnerabilities in Microsoft Office Web Apps Server 2013 that could allow remote code execution if an authenticated attacker sends specially crafted page content to a targeted computer that is running Microsoft SharePoint Server.
Improvements and fixes
This update also contains fixes for the following nonsecurity issues:- When you open and save a workbook that contains Time Grouping data in the Excel Data Model in Excel Web App, the data is lost.
- Updates the color scheme in PowerPoint Web App. It matches the color scheme when you present a PowerPoint presentation in Skype for Business.