In today’s world cyber-attacks are triggered to alter or steal the information of a person or an organization in a huge volume of data. It is very much important to protect the data/database from security related attacks.
SQL injection is one of the top trending cyber attack techniques recognized by the world’s top non-profit security foundation OWASP (Open Web Application Security Project). SQL injection attacks are made by inserting or injecting the SQL query input from the client end of the application. In this article, we will learn about the SQL injection, types of attacks using SQL injection and preventive steps.
SQL injection attack is used to insert malicious SQL statements into an entry field for execution. This injection technique is the most common web application hacking attack that allows an attacker to get unauthorised access, commit identity spoofing, tamper, take control or destroy your database. This is an attack that is very simple and easy to carry out even for script kiddies.
As we can see in the above picture, this is the second most common vulnerability that can impact databases. SQL injection flaws occur because of poorly designed web applications that can exploit SQL statements that execute malicious code.
How SQL injection is used is very much dependent on the intention of the hacker. With unauthorized access to a database server, what can attackers do? Here are some examples:
To understand SQL injection, you need to know what SQL is.
SQL – SQL stands for Structured Query Language. This language is mainly developed for interacting with the relational database. For data manipulation, Query is used to insert data, modify the database, or just to access the required data.
SQL Injection is one of the most vulnerable threats which may exploit the entire database of any private organization or government sector where code is injected in a web page.
An SQL statement will be altered in a manner which goes with ALWAYS TRUE as constraint. (In simple words 1=1 This will be always true) It allows an attacker to view unauthorized data. This might include data belonging to other users, or any other data that the application itself is able to access. An attacker can modify or delete this data, causing persistent changes to the application’s content or behavior.
There are a wide variety of SQL injection vulnerabilities, attacks, and techniques, which arise in different situations. Some common SQL injection examples include:
Select * from USERTable where uid=‘xyz’ and pwd =’x’ or ‘5’=’5’;
which may lead to Database exploitation. Injected queries are added to the normal executable query.
As a pentester, you can use two techniques to find SQL injection vulnerabilities with high efficiency - manual and automated testing.
During application development there are set of tests performed on each level, that help to detect any SQL injection vulnerability, if it exists.
There are many good tools and frameworks available in the market. Here is the list of some of the best tools for SQL injection detection.
To prevent or avoid SQL injection vulnerability, we must first understand why it occurs, and why it is listed as one of the vulnerabilities in the OWASP top 10.
Below is the vulnerable code for SQL injection where the user input is concatenated directly into the query:
Check out the code below that helps to prevents the user input from interfering with the query structure:
PreparedStatement statement = connection.prepareStatement("SELECT * FROM products WHERE category = ?"); statement.setString(1, input); ResultSet resultSet = statement.executeQuery();
It is also important to get patch updates regularly, as every day there are many new vulnerabilities that are found.
It is also recommended to use a Web Application Firewall to protect your application, which can help you to filter and find malicious data.
Where Do We Go Next?
It is very important to identify and mitigate this notorious vulnerability and take immediate actions to keep your systems secure. Many skilled attackers are waiting to take advantage of your mistakes, like poor code, so that they can hack into the database. We know this vulnerability is very old but we have to be aware of the outcomes of this type of vulnerability and try to prevent this during the development phase, rather than covering up the liability later.
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