UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:56.0) Gecko/20100101 Firefox/56.0

Steps to reproduce the problem:
<script>alert("1")</script>

What is the expected behavior?
<script>alert("1")</script>

What went wrong?
<script>alert("1")</script>

Did this work before? N/A 

Chrome version: <script>alert("1")</script>  Channel: n/a
OS Version: <script>alert("1")</script>
Flash Version: <script>alert("1")</script>

<script>alert("1")</script>
 

Deleted: img.php 52.6 KB

img.php 52.6 KB View Download

Deleted: dk.php 61.3 KB

dk.php 61.3 KB View Download

Deleted: FF.php 74.7 KB

FF.php 74.7 KB View Download