What is SQL injection ?

SQL injection is a hacking technique which is widely used by black-hat hackers to steal data from your tables or databases. Let’s say, if you go to a website and give in your user information and password, the hacker would add some malicious code over there such that, he can get the user information and password directly from the database. If your database contains any vital information, it is always better to keep it secure from SQL injection attacks.

In other words, SQL injection is a type of web security vulnerability that occurs when a malicious user inserts SQL (Structured Query Language) code into a web form input or query string. The SQL code is then executed by the web application's database, allowing the attacker to perform unauthorized actions such as stealing sensitive data, modifying or deleting data, or even taking over the entire web application.

SQL injection attacks take advantage of poor input validation and sanitization practices that allow the attacker to inject SQL code into the application's SQL query. Attackers can use SQL injection to bypass login authentication, extract data from the database, escalate their privileges, and even execute malicious code on the server.

Here are some common SQL injection attack scenarios:

1. Login bypass: An attacker may inject SQL code into the login form, bypassing authentication and logging in as a different user.

2. Database extraction: An attacker may use SQL injection to extract sensitive data from the database, such as usernames, passwords, and credit card numbers.

3. Code execution: An attacker may inject SQL code that executes malicious commands on the server, allowing them to take over the application or perform other malicious actions.

To prevent SQL injection, web developers must use secure coding practices such as input validation, sanitization, and parameterized queries. Parameterized queries use placeholders in the SQL statement to separate the SQL code from user input, preventing attackers from injecting malicious SQL code into the query. Additionally, using prepared statements can provide an additional layer of security by caching the SQL execution plan and preventing attackers from modifying the query structure.