Microsoft Excel 2000 through 2004 allows user-assisted attackers to execute arbitrary code via a .xls file with a crafted BIFF record with an attacker-controlled array index that is used for a function pointer, aka "Malformed OBJECT record Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A950
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2006/ms06-037
http://www.vupen.com/english/advisories/2006/2755
http://www.securityfocus.com/bid/18886
http://www.securityfocus.com/archive/1/439884/100/0/threaded