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 clientside 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.