Microsoft Internet Explorer 6 through 9 does not properly use the Content-Disposition HTTP header to control rendering of the HTTP response body, which allows remote attackers to read content from a different (1) domain or (2) zone via a crafted web site, aka "Content-Disposition Information Disclosure Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14614
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-099