As some questions have come up, we wanted to provide some clarification to the blog post
“Important Security Update – Zend Platform Vulnerability” posted of July, 5, 2012.
As outlined in that post, all Magento merchants on a deployed platform are strongly recommended to protect themselves from the Zend Framework vulnerability.
We have added further instructions on how to protect your business. Please apply the solution below that corresponds to your version of Magento.