Southern writes:  

Several high-profile hacks over the past year including those at Heartland, Hannaford Bros., and 7-11, all have had one thing in common: they were launched with a SQL injection attack.

Cross-site scripting (XSS) had been the king of Web attack techniques for some time, and for good reason -- the ability to steal user credentials, hijack active Web sessions and take action on behalf of a user without their knowledge is particularly nasty. But the classic SQL injection attack has regained the lead as the most popular of Web attacks. Most of all reported Web breaches the first half of this year, according to the new Web Hacking Incidents Database (WHID) report, were conducted via SQL injection. And SQL injection is one of the most common vulnerabilities in Web applications today.

SQL injection attacks take advantage of an application not validating input (like on Twitter and Facebook), or input into a form, such as a site search. The user's input is then incorrectly executed by the backend database server and can have a myriad of results. The simplest example is entering a single quote (') into a search field or login form, and receiving an error message that the SQL query failed.

The attack basically lets the bad guy take an ordinary input field and abuse it in ways that allows him to bypass authentication into the Website, manipulate the database to disclose large amounts of data, or access and control the database server itself.

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