4.3.7 Mitigation Strategies

SQL Injection Prevention - OWASP Cheat Sheet Series

Mitigation Strategies

Mitigating SQL injection vulnerabilities is crucial for securing web applications. Here are some effective strategies that can be proposed to clients to address and prevent SQL injection attacks:

Prepared Statements

Description:

• What it is:

  • Prepared statements separate SQL code from user inputs by using bind variables.

  • This is considered the best solution to mitigate SQL injection.

• Implementation Example (PHP):

  $sql = "INSERT INTO test_table VALUES (?, ?, ?, ?)";
  $sql_statement = $mysqli->prepare($sql);
  $sql_statement->bind_param('dsss', $user_id, $name, $address, $email);
  $user_id = $_POST['user_id'];
  $name = $_POST['name'];
  $address = $_POST['address'];
  $email =  $_POST['email'];
  $sql_statement->execute();

Recommendation:

• Implementing prepared statements might require code refactoring but provides a robust long-term solution.

Type Casting

Description:

• What it is:

  • Type casting involves explicitly converting user inputs to a specific data type, particularly useful for integer numbers.

• Implementation Example (PHP):

  $user_id = (int) $user_id;

Recommendation:

• Type casting offers a short-term method to prevent SQL injection, especially for numeric values.

Input Validation

Description:

• What it is:

  • Input validation checks user inputs against a predefined set of rules, allowing only valid inputs.

• Implementation Example (PHP):

  if (!preg_match('|^[a-z\s-]$|i', $name)) {
      die('Please enter a valid name');
  }

Recommendation:

• Input validation acts as a good practice to supplement other security measures.

• White-list-based validation, allowing only specific characters, can enhance security.