Microsoft Excel 2007 SP3, Excel 2010 SP2, Excel 2013 SP1, Excel 2013 RT SP1, Office for Mac 2011, Excel Viewer 2007 SP3, Office Compatibility Pack SP3, Excel Services on SharePoint Server 2007 SP3, Excel Services on SharePoint Server 2010 SP2, and Excel Services on SharePoint Server 2013 SP1 allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted Office document, aka "Microsoft Office Memory Corruption Vulnerability."
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-070