source: http://www.securityfocus.com/bid/16286/info
 
AOblogger is prone to multiple input-validation vulnerabilities. These issues are due to a failure in the application to properly sanitize user-supplied input.
 
Successful exploitation of these vulnerabilities could allow an attacker to:
 
- compromise the application
- access, modify, or create data
- steal cookie-based authentication credentials.
 
An attacker may also be able to exploit vulnerabilities in the underlying database implementation and to launch other attacks.
 
Version 2.3 is vulnerable; other versions may also be affected. 

An SQ- injection example has been provided:
http://www.example.com/aoblogger/login.php
username: username'/*
password: any 