WP Symposium Plugin for WordPress contains a flaw that allows a remote attacker to execute arbitrary PHP code. This flaw exists because the /wp-symposium/server/file_upload_form.php script does not properly verify or sanitize user-uploaded files. By uploading a .php file, the remote system will place the file in a user-accessible path. Making a direct request to the uploaded file will allow the attacker to execute the script with the privileges of the web server.