http request smuggling in pscp.tv and periscope.tv

How it was found

Description: the Description of HTTP request smuggling attacks : here

seems that many subdomains in pscp.tv and periscope.tv vulenrable

##1-Detect HTTP request smuggling attack [504 response with delay (30 s, 60s)] "DoS"

POC & Steps To Reproduce: in this video F606648 Resource: [https://portswigger.net/web-security/request-smuggling/finding]

##2- [exploit HTTP request smuggling attack ] send two request as one request get two response as one response [low impact] POC & Steps To Reproduce & impact : in this video F606663 ps: -add the two CRLFs in the end of the second request in GET REQUEST. -use the valid value of content-length in POST REQUEST.

##3-[exploit HTTP request smuggling attack ] poison the VICTIM request

POC & Steps To Reproduce & impact : in this video inject a get request to the victim request F606689 inject a get request to the victim request F606704 ps: -don't add the two CRLFs in the end of the second request in GET REQUEST. -use large value in content-length then the length of request body in POST REQUEST. Resource: [exploit] (https://portswigger.net/web-security/request-smuggling/exploiting)

important:

on a live site with a high volume of traffic like [www.pscp.tv] .it can be hard to prove request smuggling exists without exploiting numerous genuine users in the process. -in the poc F606704 , i edit the victim request to my post request editing the description of my account and ignore the real victim request. and the description will change.

Impact

1-dos 2-bypass csrf token & inject cookie allow to link attacker account with [google,twitter] victim account report : https://hackerone.com/reports/704489 see other impact in https://portswigger.net/web-security/request-smuggling/exploiting