A successful exploit of a DNS rebinding attack turns a victim’s browser into a proxy for attacking screened devices on the user’s private network, which are not exposed to the public internet. Rather than being a “standalone” vulnerability, it is typically used to enable further, onward attacks against devices that an individual or organisation may believe are inaccessible to attackers. DNS rebinding attacks aren’t as well known of or understood by organisations in the same way as household-name exploits such as “XSS”, and so many organisations may not have explicit protection measures in place.

In this article we’re going to take a look at so-called “Session Puzzling Attacks.” So in this article we’re going to step through a full explanation of typical session handling mechanisms, how the vulnerability can arise within them, and how to prevent vulnerabilities of this class.