source: https://www.securityfocus.com/bid/23616/info
 
Phorum is prone to multiple input-validation vulnerabilities, including an unauthorized-access issue, privilege-escalation issue, multiple SQL-injection issues, and cross-site scripting issues, because the application fails to sufficiently sanitize user-supplied input.
 
Exploiting these issues could allow an attacker to steal cookie-based authentication credentials, compromise the application, access or modify sensitive data, or exploit latent vulnerabilities in the underlying database implementation.
 
Phorum 5.1.20 is affected; prior versions may also be vulnerable.

http://localhost/phorum.5.1.20/admin.php?module=modsettings&mod=smileys&
edit=1&smiley_id="><script>alert(123);</script>