Heap-based buffer overflow in Microsoft Office Excel 2002 SP3, Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac allows remote attackers to execute arbitrary code via a spreadsheet containing a malformed Binary File Format (aka BIFF) record that triggers memory corruption, aka "Excel Document Parsing Heap Overflow Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6137
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-067