Buffer overflow in Microsoft Office Excel 2002 SP3, Office 2004 for Mac, Office 2008 for Mac, and Open XML File Format Converter for Mac allows remote attackers to execute arbitrary code via an Excel file with a malformed ExternName (0x23) record, aka "Excel Memory Corruption Vulnerability," a different vulnerability than CVE-2010-0823 and CVE-2010-1247.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6634
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-038
http://www.us-cert.gov/cas/techalerts/TA10-159B.html
http://www.securityfocus.com/bid/40527
http://www.securityfocus.com/archive/1/511767/100/0/threaded