Tapatalk Plugin for XenForo and vBulletin suffer of Open redirect.

Vendor: http://tapatalk.com

Dork: inurl: mobiquo/mobiquo.php

Plugin versions:
Tapatalk plugin for vBulletin: 5.2.2
Tapatalk plugin for Xenforo: <2.3.5

Description:
Tapatak Plugin allow to arbitrary redirect users to external websites

PoC:
http://www.example.com/mobiquo/mobiquo.php?welcome=1&referer=http%3A%2F%2Finforge.net%2F

How to fix:
Update the latest version.