source: http://www.securityfocus.com/bid/53208/info

The CCNewsLetter module for Joomla! is prone to an SQL-injection vulnerability because it fails to sufficiently sanitize user-supplied data before using it in an SQL query.

A successful exploit may allow an attacker to compromise the application, access or modify data, or exploit latent vulnerabilities in the underlying database.

CCNewsLetter 1.0.7 is vulnerable; prior versions may also be affected. 

 http://www.example.com/modules/mod_ccnewsletter/helper/popup.php?id=[SQLi]