I found a vulnerability en phpbb 2.0.5 and prior, is probably also affect 2.0.6
this bug don't affect to version 2.0.7
phpbb have a list of registereds users, when you click on a memebr of this list, you are requesting data to the database
for example:
http://www.example.com/forum/profile.php?mode=viewprofile&u=2
this url show the information to the user with the uid = 2, the uid is a number
assigned to users in phpbb.
but it isn't secure, because if you use this url, you can inject sql comands...
exploit:
http://www.example.com/profile.php?mode=viewprofile&u='[sqlcode]
where [sql code] represents the code may be injected.