source: http://www.securityfocus.com/bid/14195/info

PunBB is affected by a SQL injection vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input through the user profile edit module of the 'profile.php' script before using it in a 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.

This issue may be successfully exploited to gain administrative access to a vulnerable forum.

PunBB 1.2.5 and prior versions are vulnerable. 

Injecting the following can allow the attacker to gain administrative privileges:

temp[0]=group_id=1