Lack of protection against brute force attacks

Need

Implementation of strong authentication and rate limiting mechanisms

Context

• Usage of Scala 2.12 for developing scalable and high-performance applications
• Usage of play.api.mvc for handling HTTP requests and responses in Play Framework
• Usage of play.api.data for handling form data in Play Framework
• Usage of play.api.data.Forms for handling form data in Play Framework
• Usage of models.User for accessing and manipulating user data

Description

Non compliant code

import play.api.mvc._
import play.api.data._
import play.api.data.Forms._

case class UserData(name: String, password: String)

val userForm = Form(
  mapping(
    "name" -> text,
    "password" -> text
  )(UserData.apply)(UserData.unapply)
)

def login = Action { implicit request: Request[AnyContent] =>
  val userData = userForm.bindFromRequest.get
  val user = models.User.find(userData.name, userData.password)
  user match {
    case Some(u) => Ok("You are logged in.")
    case None => Unauthorized("Wrong credentials.")
  }
}

This code defines a simple login action in a Scala Play Framework application. The login action takes a request, binds the request data to a UserData case class (which contains a username and password), and then attempts to find a user in the database with the provided credentials. If a user is found, the action responds with "You are logged in.". If no user is found, the action responds with "Unauthorized".

The vulnerability lies in the fact that there are no protections against brute force attacks. A brute force attack involves an attacker systematically checking all possible passwords until the correct one is found. In this case, an attacker could potentially make unlimited login attempts with different passwords until they guess correctly.

There are no mechanisms in place to limit the number of login attempts or to introduce a delay after a certain number of failed attempts. Furthermore, the application does not use any sort of CAPTCHA or other challenge-response test to ensure that the login attempts are being made by a human rather than a script. As a result, this code is highly susceptible to brute force attacks.

Steps

• Implement a rate limiting mechanism to limit the number of login attempts from a single IP address within a certain time period.
• Implement account lockout after a certain number of failed login attempts to prevent brute force attacks.
• Enforce strong password policies, such as requiring a minimum password length, complexity, and expiration.
• Implement multi-factor authentication to add an extra layer of security to the login process.
• Use a secure password hashing algorithm, such as bcrypt, to store user passwords.
• Implement CAPTCHA or other challenge-response mechanisms to differentiate between human and automated login attempts.
• Implement logging and monitoring to detect and respond to suspicious login activities.
• Regularly update and patch the application and its dependencies to address any security vulnerabilities.
• Educate users about the importance of using strong passwords and avoiding password reuse.

Compliant code

import play.api.mvc._
import play.api.data._
import play.api.data.Forms._
import play.api.libs.concurrent.Execution.Implicits.defaultContext
import scala.concurrent.duration._
import play.filters.throttle.ThrottleFilter

case class UserData(name: String, password: String)

val userForm = Form(
  mapping(
    "name" -> text,
    "password" -> nonEmptyText(minLength = 8)
  )(UserData.apply)(UserData.unapply)
)

def login = Action.async { implicit request: Request[AnyContent] =>
  val userData = userForm.bindFromRequest.get
  val user = models.User.find(userData.name, userData.password)
  user match {
    case Some(u) => Ok("You are logged in.")
    case None => 
      models.User.incrementFailedAttempts(userData.name)
      if (models.User.checkFailedAttempts(userData.name) >= 5) {
        models.User.lockAccount(userData.name)
        Future.successful(Forbidden("Account locked due to too many failed attempts."))
      } else {
        Future.successful(Unauthorized("Wrong credentials."))
      }
  }
}

// Throttle filter to limit requests
class Filters @Inject() (throttleFilter: ThrottleFilter) extends HttpFilters {
  def filters = Seq(throttleFilter)
}

The updated code includes several measures to protect against brute force attacks:

1. Rate Limiting: The ThrottleFilter is used to limit the number of login attempts from a single IP address within a certain time period. This is a simple yet effective way to prevent automated attacks from flooding the server with login requests.

2. Account Lockout: After a certain number of failed login attempts (in this case, 5), the user's account is locked. This prevents further login attempts, thwarting brute force attacks.

3. Strong Password Policies: The nonEmptyText(minLength = 8) form constraint is used to enforce a minimum password length of 8 characters. This makes it harder for attackers to guess the password.

4. Secure Password Hashing: Although not shown in the code, it is recommended to use a secure password hashing algorithm, such as bcrypt, to store user passwords. This ensures that even if the password database is compromised, the attacker cannot easily obtain the original passwords.

5. Logging and Monitoring: The incrementFailedAttempts and checkFailedAttempts methods (not shown in the code) can be used to log and monitor failed login attempts. This allows administrators to detect and respond to suspicious activities.

6. Regular Updates and Patches: Although not shown in the code, it is important to regularly update and patch the application and its dependencies to address any security vulnerabilities.

7. User Education: Although not part of the code, educating users about the importance of using strong passwords and avoiding password reuse can significantly improve the security of the system.

References

• 053.Lack of protection against brute force attacks