I am facing some issue of "Open Redirect", is there any direct solution or document which may help me.
pagereference p = new pagereference(returnUrl); return p;
here Security issue is
Open Redirect Vulnerability
An open redirect is an application that takes a parameter and redirects a user to the parameter value without any validation. This vulnerability is used in phishing attacks to get users to visit malicious sites without realizing it.
I have redirect urls in alomost each class of mine.