Microsoft Internet Explorer 6 through 9 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code via an attempted access to a virtual function table after corruption of this table has occurred, aka "Virtual Function Table Corruption Remote Code Execution Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12223
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-081