Secure Your MySQL Login Form

TL;DR

Your MySQL login form is vulnerable to attacks if you don’t protect it properly. This guide shows you how to prevent common issues like SQL injection and weak passwords, making your database much safer.

1. Understand the Risks

Attackers can exploit weaknesses in your login form to:

• Gain unauthorised access to your database.
• Steal sensitive data.
• Modify or delete important information.

2. Prevent SQL Injection

SQL injection happens when attackers insert malicious code into the username or password fields. Here’s how to stop it:

1. Use Prepared Statements: This is the most effective method. Prepared statements separate the SQL code from the user input, preventing the database from interpreting the input as part of the query.

   // Example using PDO in PHP
   $stmt = $pdo->prepare('SELECT * FROM users WHERE username = ? AND password = ?');
   $stmt->execute([$username, $password]);
   

2. Input Validation: Check the length and format of user input. For example, limit usernames to a certain number of characters and only allow alphanumeric characters.

   // Example in PHP
   if (strlen($username) > 50 || !ctype_alnum($username)) {
     echo 'Invalid username';
   }
   

3. Escaping User Input: If you absolutely cannot use prepared statements, escape special characters. However, this is less secure than using prepared statements.

   // Example in PHP (use with caution!)
   $username = mysqli_real_escape_string($conn, $username);
   

3. Secure Password Storage

Never store passwords in plain text! Here’s how to do it right:

1. Hashing: Use a strong hashing algorithm like bcrypt or Argon2.

   // Example using PHP's password_hash function
   $hashedPassword = password_hash($password, PASSWORD_DEFAULT);
   

2. Salting: A salt is a random string added to the password before hashing. This makes it harder for attackers to crack passwords even if they get access to your database.

   PASSWORD_DEFAULT automatically handles salting.

3. Password Verification: Use password_verify() to check if a user’s entered password matches the stored hash.

   // Example using PHP
   if (password_verify($enteredPassword, $hashedPassword)) {
     echo 'Login successful!';
   }
   

4. Implement Rate Limiting

Rate limiting restricts the number of login attempts from a single IP address within a certain time period. This helps prevent brute-force attacks.

• Store Login Attempts: Keep track of failed login attempts for each IP address.
• Block Suspicious IPs: If an IP address exceeds the limit, temporarily block it.

5. Use Strong Passwords

Encourage users to create strong passwords:

• Minimum Length: Require a minimum password length (e.g., 8 characters).
• Complexity: Enforce the use of uppercase and lowercase letters, numbers, and symbols.
• Password Strength Meter: Consider using a password strength meter to provide feedback to users.

6. Keep Software Updated

Regularly update your database server, web server, and any related software to patch security vulnerabilities.

7. Enable cyber security Logging & Monitoring

Keep detailed logs of all login attempts (successful and failed). Monitor these logs for suspicious activity.