Use of an insecure channel - Telnet - Scala

Need

Secure communication channel for transmitting customer information

Context

1. Usage of Scala for building scalable and functional applications
2. Usage of Play Framework for building web applications in Scala or Java
3. Usage of java.net.Socket for network communication
4. Usage of java.io.* for input/output operations in Java

Description

Insecure Code Example

import java.net.Socket
import java.io._
import play.api._
import play.api.mvc._

// Controller for handling requests
class HomeController extends Controller {
  def sendInfo = Action { request =>
    val socket = new Socket("localhost", 23)
    val out = new PrintWriter(socket.getOutputStream, true)
    val in = new BufferedReader(new InputStreamReader(socket.getInputStream))

    // Sending customer information over insecure Telnet channel
    out.println("Customer Username: " + request.body.asFormUrlEncoded.get("username").mkString)
    out.println("Customer Password: " + request.body.asFormUrlEncoded.get("password").mkString)

    socket.close()
    Ok("Information sent")
  }
}

The above Scala code snippet is a part of a Play Framework backend application. It represents a controller named `HomeController` that has a method `sendInfo`, which is used to send customer data. The vulnerability lies in the `sendInfo` method where it opens a socket to a localhost on port 23, which is the default port for Telnet. Telnet is an insecure protocol as it does not encrypt its data. This means that any data sent over this protocol can be easily captured in plain text. The method then creates a `PrintWriter` for sending data over the socket and a `BufferedReader` for reading data from the socket. The customer's username and password are then retrieved from the request body and sent over the Telnet channel using the `PrintWriter`. The use of Telnet to transmit sensitive information such as usernames and passwords constitutes a major security vulnerability. An attacker can easily intercept the data transmission and gain unauthorized access to the customer's information.

Steps

1. Replace the insecure Telnet channel with a secure channel that uses encryption, such as HTTPS.
2. Use a secure communication protocol, such as TLS/SSL, to encrypt the data transmitted over the channel.
3. Update the code to use a secure socket implementation, such as SSLSocket, instead of the plain Socket class.
4. Obtain a valid SSL certificate for the server to ensure secure communication.
5. Configure the server to use the secure channel and enforce HTTPS for all requests.
6. Ensure that the client-side code also uses HTTPS when making requests to the server.
7. Implement proper authentication and authorization mechanisms to protect customer information.
8. Consider using additional security measures, such as encryption of sensitive data at rest and in transit.

Secure Code Example

import java.net.Socket
import javax.net.ssl.{SSLSocketFactory, SSLSocket}
import java.io._
import play.api._
import play.api.mvc._

// Controller for handling requests
class HomeController extends Controller {
  def sendInfo = Action { request =>
    val socketFactory: SSLSocketFactory = SSLSocketFactory.getDefault().asInstanceOf[SSLSocketFactory]
    val socket: SSLSocket = socketFactory.createSocket("localhost", 443).asInstanceOf[SSLSocket]
    val out = new PrintWriter(socket.getOutputStream, true)
    val in = new BufferedReader(new InputStreamReader(socket.getInputStream))

    // Sending customer information over secure SSL channel
    out.println("Customer Username: " + request.body.asFormUrlEncoded.get("username").mkString)
    out.println("Customer Password: " + request.body.asFormUrlEncoded.get("password").mkString)

    socket.close()
    Ok("Information sent")
  }
}

The updated code replaces the insecure Telnet channel with a secure SSL channel. The `Socket` class is replaced with `SSLSocket`, which is a secure socket using SSL/TLS protocols to encrypt the data transmitted over the channel. The `SSLSocketFactory` is used to create the `SSLSocket`. The `SSLSocketFactory` is obtained by calling the `getDefault` method, which returns the default SSL socket factory. The default SSL socket factory is determined by the system property `javax.net.ssl.SSLSocketFactory`. If this system property is not set, the default SSL socket factory is an instance of `javax.net.ssl.SSLSocketFactory`. The `SSLSocket` is created by calling the `createSocket` method on the `SSLSocketFactory`, passing the server's hostname and port number as arguments. The port number is changed from 23 (the default port for Telnet) to 443 (the default port for HTTPS). The customer's username and password are sent over the secure SSL channel by calling the `println` method on the `PrintWriter` object, which is created by passing the `SSLSocket`'s output stream to the `PrintWriter` constructor. The `SSLSocket` is closed after the customer's information is sent. The server must be configured to use the secure channel and enforce HTTPS for all requests. The client-side code must also use HTTPS when making requests to the server. Proper authentication and authorization mechanisms should be implemented to protect customer information. Additional security measures, such as encryption of sensitive data at rest and in transit, should be considered.

References

Last updated

2023/09/18