Integer overflow in Microsoft Internet Explorer 8 and 9, JScript 5.8, and VBScript 5.8 on 64-bit platforms allows remote attackers to execute arbitrary code by leveraging an incorrect size calculation during object copying, aka "JavaScript Integer Overflow Remote Code Execution Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15790
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-056
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-052