Even today, a single poorly written SQL query can allow an attacker to bypass authentication or expose sensitive data. And the scary part? It often comes down to just one line of code. In the previous articles, we saw how small implementation decisions can introduce serious vulnerabilities. SQL Injection is one of the clearest examples of this—simple to understand, yet still widely exploited. What is SQL Injection? SQL Injection occurs when untrusted user input is included directly in a SQL query . Instead of being treated as data, the input is interpreted as part of the SQL command itself. This allows attackers to manipulate queries and control how the database behaves. How SQL Injection Works Consider a typical login query: SELECT * FROM users WHERE username = 'input' AND password = 'input'; The application expects input to be normal user data. But what if an attacker provides this instead?…