== Compromising confidentiality with String SQL injection If a system is vulnerable to SQL injections, aspects of that system's CIA triad can be easily compromised _(if you are unfamiliar with the CIA triad, check out the CIA triad lesson in the general category)_. In the following three lessons you will learn how to compromise each aspect of the CIA triad using techniques like _SQL string injections_ or _query chaining_. In this lesson we will look at *confidentiality*. Confidentiality can be easily compromised by an attacker using SQL injection; for example, successful SQL injection can allow the attacker to read sensitive data like credit card numbers from a database. === What is String SQL injection? If an application builds SQL queries simply by concatenating user supplied strings to the query, the application is likely very susceptible to String SQL injection. + More specifically, if a user supplied string simply gets concatenated to a SQL query without any sanitization or preparation, then you may be able to modify the query's behavior by simply inserting quotation marks into an input field. For example, you could end the string parameter with quotation marks and input your own SQL after that. === It is your turn! You are an employee named John *Smith* working for a big company. The company has an internal system that allows all employees to see their own internal data such as the department they work in and their salary. The system requires the employees to use a unique _authentication TAN_ to view their data. + Your current TAN is *3SL99A*. Since you always have the urge to be the most highly paid employee, you want to exploit the system so that instead of viewing your own internal data, _you want to take a look at the data of all your colleagues_ to check their current salaries. Use the form below and try to retrieve all employee data from the *employees* table. You should not need to know any specific names or TANs to get the information you need. + You already found out that the query performing your request looks like this: ------------------------------------------------------------ "SELECT * FROM employees WHERE last_name = '" + name + "' AND auth_tan = '" + auth_tan + "'"; ------------------------------------------------------------