Introduction to SQL Injection

#Understanding SQL Injection (SQLi)#link

SQL Injection is a code injection technique where malicious SQL statements are inserted into entry fields for execution. This can allow attackers to bypass authentications, retrieve database contents, or escalate privileges.

How SQLi Works Conceptually

// VULNERABLE CODE (String Concatenation)
const query = "SELECT * FROM users WHERE username = '" + userInput + "' AND password = '" + userPass + "'";

If the attacker inputs `' OR '1'='1` as the username, the query becomes:

SELECT * FROM users WHERE username = '' OR '1'='1' AND password = '...';