source: https://www.securityfocus.com/bid/16249/info

geoBlog 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.

The following proof of concept URI is available:
http://www.example.com/geoblog/viewcat.php?cat=I'%20union%20select%201,2,3,4,5,6,7/*