What is SQL Injection -

What is SQL Injection?

SQL injection is a type of cyber attack that targets the database layer of a web application. It occurs when an attacker inserts malicious SQL code into user inputs, tricking the application into executing unintended SQL queries. The primary goal of such attacks is unauthorized access to the database, extraction of sensitive information, or even manipulation of data.

In the below PDF we discuss about SQL Injection in detail in simple language, Hope this will help in better understanding.

Common SQL Injection Techniques:

1. Classic SQL Injection:
In this method, attackers manipulate input fields such as login forms or search boxes to inject malicious SQL code. For example, by entering ‘ OR ‘1’=’1′ in a login form, an attacker could potentially bypass authentication checks.

2. Blind SQL Injection:
In a blind SQL injection, attackers exploit vulnerabilities without directly retrieving data from the database. Instead, they determine the validity of certain conditions by observing the application’s behavior. This can be a time-consuming process, but it allows attackers to gather information stealthily.

3. Time-Based Blind SQL Injection:
This technique involves inducing delays in the server’s response to infer whether a specific condition is true or false. By carefully crafting SQL queries, attackers can exploit this delay to gain insights into the database structure or extract sensitive information.

Various Attack Vectors:

User Input Fields: Web applications frequently incorporate user input fields for search queries, login credentials, and other interactive elements. If these inputs are not adequately checked or sanitised, attackers may introduce harmful SQL code.
URL Parameters: URLs may include parameters that are utilised in database queries. If these parameters are not handled properly, they can be used for SQL injection attacks.
Cookies: Cookies are another potential attack channel. If a web application keeps user data in cookies without adequately validating or sanitising it, attackers can exploit cookies to inject malicious SQL code.

Preventing SQL Injection:

Parameterized Queries: Use parameterized queries or prepared statements to ensure that user inputs are treated as data and not executable code. This helps to separate user input from SQL commands.
Input Validation and Sanitization: Implement robust input validation and sanitization techniques to ensure that user inputs adhere to expected formats and do not contain malicious code.
Least Privilege Principle: Limit the database user’s privileges to the minimum necessary for its functionality. Avoid using accounts with excessive permissions, as this can mitigate the potential impact of a successful SQL injection attack.
Regular Security Audits: Conduct regular security audits and vulnerability assessments to identify and address potential SQL injection vulnerabilities before attackers can exploit them.