SQL Injection

SQL Injection is a technique used by attackers to execute malicious SQL queries by inserting harmful input into an application's SQL statements.

SQL Injection is a security vulnerability where an attacker inserts malicious SQL code into an input field (like login forms, search boxes, URLs) to manipulate or access the database. It commonly affects applications using databases such as Microsoft SQL Server.

Types of SQL Injection:
1️. Login Bypass Injection
Used to bypass authentication.
Example:
' OR '1'='1
2️. Data Extraction Injection
Attackers retrieve sensitive data.
Example:
SELECT * FROM Users;
3️. Blind SQL Injection
Database responses are not visible, but attackers infer information using true/false conditions. 4️. Error-Based Injection
Attackers analyze database error messages to understand the structure.

How to Prevent SQL Injection
1️. Use Parameterized Queries
SELECT *
FROM Users
WHERE Username = @Username
AND Password = @Password;
2️. Use Stored Procedures
Stored procedures prevent direct SQL query manipulation.
3️. Input Validation
Check user inputs for special characters.
4️. Use ORM or Framework Security
Most frameworks automatically prevent SQL injection.

SQL injection can allow attackers to:

Steal sensitive data
Delete database records
Modify data
Gain admin access
Crash the database

Exam/Interview Definition:
SQL Injection is a security attack where malicious SQL statements are inserted into input fields to manipulate or access a database.