Which of the following BEST describes a protective countermeasure for SQL injection?

A.
Eliminating cross-site scripting vulnerabilities

B.
Installing an IDS to monitor network traffic

C.
Validating user input in web applications

D.
Placing a firewall between the Internet and database servers

Explanation:
By validating user input and preventing special characters, we can prevent the injection of client-side scripting
code.
SQL injection is a code injection technique, used to attack data-driven applications, in which malicious SQL
statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker).
SQL injection must exploit a security vulnerability in an application’s software, for example, when user input is
either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not
strongly typed and unexpectedly executed. SQL injection is mostly known as an attack vector for websites but
can be used to attack any type of SQL database.