Microsoft Excel 2002 SP3 and 2003 SP3, Office 2004 and 2008 for Mac, and Open XML File Format Converter for Mac allow remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted HLink record in an Excel file, aka "Excel Buffer Overwrite Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11767
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-021
http://www.vupen.com/english/advisories/2011/0940
http://www.us-cert.gov/cas/techalerts/TA11-102A.html
http://www.securitytracker.com/id?1025337
http://www.securityfocus.com/bid/47245
http://www.checkpoint.com/defense/advisories/public/2011/cpai-31-Mard.html