WAF: Wrong Approach Firewall (gpn24) (opens in new tab)

Web Application Firewalls (WAFs) for filtering based on HTTP and payload are omnipresent. In this talk an argument will be made that, in many cases, the wrong approach for implementing WAFs is chosen: They are implemented as "deny firewalls" which specifically forbid "bad" traffic based on pattern rules, while for network security (layers 3/4) professionals would only ever follow an "allow firewall" approach, which explicitly lets "good" traffic pass and denies everything else. "deny WAFs" ar...