Some days ago a security advisory related to web application firewalls (WAFs) was published on Full Disclosure. Wendel Guglielmetti Henrique found another bug in the IBM Web Application Firewall which can be used to circumvent the WAF and execute typical web application attacks like SQL injection (click here for details). Wendel talked already (look here) at the Troopers Conference in 2009 about the different techniques to identify and bypass WAFs, so this kind of bypass methods are not quite new.
Continue reading