SQL injection in Cybersecurity - Mini Project: Build & Apply

Understanding SQL Injection

📖 Scenario: You are learning about web security. Many websites use databases to store user information. Sometimes, if the website code is not careful, attackers can trick the database with special inputs. This is called SQL injection.Imagine a website login form that asks for a username and password. If the website does not check the input properly, an attacker can enter code that changes the database query and gains access without a real password.

🎯 Goal: Build a simple example of a SQL query that is vulnerable to SQL injection. Then, create a safer version that avoids this problem.

📋 What You'll Learn

Create a SQL query string that uses user input directly

Add a variable for user input representing a username

Write a SQL query that includes the username variable without safety checks

Write a safer SQL query using parameter placeholders

💡 Why This Matters

🌍 Real World

Web developers and security professionals must understand SQL injection to protect websites and user data from attackers.

💼 Career

Knowledge of SQL injection is essential for roles in cybersecurity, web development, and database administration to ensure safe and secure applications.

1

Set up the user input variable

Create a variable called username and set it to the string "admin".

Cybersecurity

# Create a variable called username and set it to "admin"
# Your code here

Need a hint?

Use the equals sign = to assign the string "admin" to the variable username.

2

Create a vulnerable SQL query string

Create a variable called query_vulnerable that builds a SQL query string by directly inserting the username variable into the query using string concatenation. The query should be: SELECT * FROM users WHERE username = ' plus the username plus ';

Cybersecurity

username = "admin"
# Create a vulnerable SQL query string using username
# Your code here

Need a hint?

Use string concatenation with + to build the query string including the username variable.

3

Explain how SQL injection can happen

Add a comment explaining that if username contains special characters like ' OR '1'='1, the query becomes unsafe and can allow unauthorized access.

Cybersecurity

username = "admin"
query_vulnerable = "SELECT * FROM users WHERE username = '" + username + "';"
# Add a comment explaining SQL injection risk
# Your code here

Need a hint?

Write a comment starting with # describing the risk of special input in username.

4

Create a safer SQL query using parameters

Create a variable called query_safe that contains the SQL query string with a parameter placeholder ? instead of inserting the username directly. The query should be: SELECT * FROM users WHERE username = ?;

Cybersecurity

username = "admin"
query_vulnerable = "SELECT * FROM users WHERE username = '" + username + "';"
# If username contains something like "' OR '1'='1", this query allows SQL injection and unauthorized access
# Create a safer SQL query string using a parameter placeholder
# Your code here

Need a hint?

Use a question mark ? as a placeholder in the query string to safely insert user input later.