Skip to main content

Privilege escalation

Need​

Enhancement of role-based access control and privilege management

Context​

  • Usage of Scala for building scalable and high-performance applications
  • Usage of Play Framework's MVC module for handling HTTP requests and responses
  • Usage of Scala's global execution context for concurrent programming

Description​

Non compliant code​

import play.api.mvc._
import scala.concurrent.ExecutionContext.Implicits.global

class AdminController @Inject()(val controllerComponents: ControllerComponents) extends BaseController {

  def adminAction = Action.async { implicit request: Request[AnyContent] =>
    val userRole = request.session.get("role")
    userRole match {
      case Some("admin") => {
        // Perform admin operations
      }
      case _ => {
        // Redirect to login or unauthorized page
      }
    }
  }
}

In the above code, the AdminController is used to handle requests that should be restricted to users with administrative privileges. The adminAction function checks the user's role from the session and allows the operation to proceed if the user is an admin.

However, this code is insecure because it trusts the user role value stored in the session. An attacker could manipulate the session data and set the "role" to "admin", thus escalating their privileges and gaining administrative access.

The vulnerability lies in the fact that the application does not verify if the user actually has the role they claim to have. It simply trusts the role value from the session. This is a classic example of a Privilege Escalation vulnerability where a standard user can obtain administrative access due to insecure role configuration.

Steps​

  • Review the role configuration to ensure that it is properly secured.
  • Implement proper authentication and authorization mechanisms to validate user roles.
  • Use a secure session management mechanism to store and retrieve user roles.
  • Ensure that only authorized users with the 'admin' role can access the adminAction method.
  • Implement proper error handling and redirect unauthorized users to a login or unauthorized page.
  • Regularly review and update the role configuration to prevent any potential privilege escalation vulnerabilities.

Compliant code​

import play.api.mvc._
import scala.concurrent.ExecutionContext.Implicits.global

class AdminController @Inject()(val controllerComponents: ControllerComponents, authService: AuthService) extends BaseController {

  def adminAction = Action.async { implicit request: Request[AnyContent] =>
    val userRole = request.session.get("role")
    authService.authenticate(userRole) match {
      case true => {
        // Perform admin operations
      }
      case false => {
        // Redirect to login or unauthorized page
      }
    }
  }
}

class AuthService {
  def authenticate(userRole: Option[String]): Boolean = {
    userRole match {
      case Some("admin") => true
      case _ => false
    }
  }
}

The updated code includes an AuthService class that is responsible for authenticating the user role. This service is injected into the AdminController and used to authenticate the user role before performing any admin operations.

In the adminAction method, the AuthService's authenticate method is called with the user role retrieved from the session. If the user role is 'admin', the authenticate method returns true and the admin operations are performed. If the user role is not 'admin', the authenticate method returns false and the user is redirected to a login or unauthorized page.

This approach ensures that only users with the 'admin' role can access the adminAction method, preventing privilege escalation vulnerabilities. It also separates the concerns of authentication and controller logic, making the code easier to maintain and test.

Remember to always use secure session management mechanisms to store and retrieve user roles, and regularly review and update the role configuration to prevent any potential privilege escalation vulnerabilities.

References​

Last updated on