Microsoft Internet Explorer 6 through 9 does not properly implement JavaScript event handlers, which allows remote attackers to access content from a different (1) domain or (2) zone via unspecified script code, aka "Event Handlers Information Disclosure Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12383
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-057