PHPBuilder is back with the second part of their excerpt from the book Pro PHP Security (Apress)looking at finding and preventing SQL injections in your applications.

Topics it's broken out into include:

• Kinds of Injection Attacks
• Multiple-query Injection
• INVISION POWER BOARD SQL INJECTION VULNERABILITY
• Demarcate Every Value in Your Queries

They start off pretty basic - watch what you're directly including in your SQL statement - and move on to how attackers can end your SQL and push in their own and more. The Invision vulnerability is a more real-world example of what can go wrong when filtering isn't done right. The tutorial's rounded off with some of the functions and methods you can use to check the input and filter out the bad from the good.