SQL injection

Need

Implementation of proper input validation and the use of parameterized statements or stored procedures to prevent SQL injection attacks.

Context

• Usage of Scala for building scalable and high-performance applications

• Usage of play.api.db for database access in Play Framework

• Usage of the Play.current object for accessing the current Play application instance

Description

1. Non compliant code

import play.api.db._
import play.api.Play.current

class UserController extends Controller {
  def getUser = Action { request =>
    // Get the username from the request parameters
    val username = request.getQueryString("username").getOrElse("")
    // Get the user from the database...

The code above is an example of a SQL injection vulnerability in a Scala backend application that uses the Play framework. In the `getUser` method, the `username` is directly obtained from the request parameters without any data validation. This `username` is then directly concatenated into a SQL SELECT statement. This approach is vulnerable to SQL injection attacks. If an attacker provides a `username` that includes SQL syntax, they could manipulate the SQL statement to return all users, delete data, or even drop tables. For example, a `username` of `' OR '1'='1` would change the SQL statement to `SELECT * FROM users WHERE username = '' OR '1'='1'`, which would return all users. To make matters worse, the SQL statement is executed with `conn.createStatement()`, which does not use any form of parameterized query or stored procedure. This means there's no mechanism in place to automatically escape special characters in the `username` that could be used for SQL injection.

2. Steps

• Use parameterized statements or prepared statements to execute SQL queries.

• Validate and sanitize user input before using it in SQL queries.

• Avoid concatenating user input directly into SQL queries.

• Implement input validation to ensure that only expected data types and formats are accepted.

• Implement proper error handling and logging to detect and respond to SQL injection attempts.

3. Secure code example

import play.api.db._
import play.api.Play.current
import anorm._

class UserController extends Controller {
  def getUser = Action { request =>
    // Get the username from the request parameters
    ...

The updated code includes several changes to mitigate the risk of SQL injection: 1. **Parameterized Query**: Instead of concatenating the username directly into the SQL query, a parameterized query is used. This ensures that the username is properly escaped, preventing any malicious SQL code from being executed. 2. **Input Validation**: The username is checked against a regular expression to ensure it only contains alphanumeric characters and underscores. This is a basic form of input validation and sanitization that can help prevent SQL injection. Depending on the specific requirements of your application, you may need to use a more complex regular expression or additional validation logic. 3. **Error Handling and Logging**: If the username does not pass the validation check, an error is logged and a response indicating invalid input is returned. This can help detect and respond to SQL injection attempts. Note: This code assumes that you are using the Anorm library, which is commonly used with the Play framework for database access. If you are using a different library, the exact syntax for parameterized queries may be different.

References

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