SQL Injection
Is one of the common ways of cracking the websites and programs that are working with databases, based on arbitrary SQL-injection in the query. SQL-injection, depending on the type of databases management system and injection conditions allows the assaulter to execute ad hoc query to the databases, get the opportunity to read and/or record the local files and perform ad hoc commands on the server under attack.
The attack caused by SQL-injection is possible due to incorrect processing of incoming data, used in SQL queries.