Microsoft Excel 2003 SP3 and 2007 SP2; Excel in Office 2007 SP2; Office 2004 and 2008 for Mac; Open XML File Format Converter for Mac; Excel Viewer SP2; and Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats SP2 do not properly parse records in Excel spreadsheets, which allows remote attackers to execute arbitrary code via a crafted spreadsheet, aka "Excel Heap Corruption Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12836
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-072