. Directories data config are not protected by htaccess in default installiation. This can be used to retrieve registered user's information including logins and password's md5 hashes.
2. Directory traversal is possible.
Vulnerable script: index.php Variable $_GET[post] isn't properly sanitized. This can be used to open arbitrary files with txt extention. Administrator's login and password is threatened.
Administrator has an ability to upload arbitrary files.