Microsoft Internet Explorer 5.01 / 5.5 DHTMLED and IFRAME File Read Vulnerability
The implementation of DHTMLED (Dynamic HTML Edit Control) in Microsoft Internet Explorer 5.5 / 5.01 makes it possible for a malicious web site operator to view the contents of known files on a remote host. This can also be exploited via HTML email if the recipient uses Outlook.
DHTML Edit Control is the mechanism which gives Internet Explorer WYSIWYG HTML editor functionality. The DOM security model is not properly recognized when IFRAMEs are used with DHTMLED. The contents of the IFRAME (which may be set up to read from known local files) can be directed to the web server by using the following code:
alert("Alert Message: "+S1.value);