What is SQL Injection? - Explanation & Meaning

Definition

SQL injection is a cyber attack technique where an attacker inserts malicious SQL code into input fields of an application to gain unauthorized access to the underlying database. It is one of the oldest and still most prevalent web vulnerabilities.

Technical explanation

SQL injection occurs when user input is included in SQL queries without validation. In a classic SQL injection, an attacker manipulates a WHERE clause by entering input like ' OR 1=1 --, causing the query to return all records. Blind SQL injection uses time delays or boolean conditions to exfiltrate data when direct output is not visible. Second-order SQL injection stores malicious input first and executes it later. The OWASP Top 10 has ranked injection at the top for years due to its high impact and prevalence. The primary defense is using parameterized queries (prepared statements) that strictly separate input from SQL code. ORM frameworks like Prisma, Drizzle, and SQLAlchemy provide built-in protection. Input validation, output encoding, and the principle of least privilege for database accounts form additional defense layers. Web Application Firewalls (WAF) detect and block suspicious SQL patterns in HTTP requests. Regular code audits and SAST tools identify potential injection vulnerabilities early in development.

How MG Software applies this

At MG Software, we exclusively use parameterized queries and ORM frameworks that prevent SQL injection by design. Our CI/CD pipeline includes automated SAST scans that detect potential injection vulnerabilities. We apply input validation on all external input and follow the least-privilege principle for database access. Code reviews include specific checkpoints for injection prevention.

Practical examples

• An online store where an attacker performs a SQL injection via the search field and downloads the entire customer database with email addresses and hashed passwords.
• A security researcher who discovers a blind SQL injection in a login form during a pen test, extracting the admin password hash character by character.
• A development team that replaces all raw SQL queries with parameterized queries via their ORM after a code audit, eliminating dozens of potential injection points.

Related terms