  We present a formal approach that exploits attacks related to SQL Injection
(SQLi) searching for security flaws in a web application. We give a formal
representation of web applications and databases, and show that our
formalization effectively exploits SQLi attacks. We implemented our approach in
a prototype tool called SQLfast and we show its efficiency on real-world case
studies, including the discovery of an attack on Joomla! that no other tool can
find.
