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Use of insecure channel - Source code

Need​

Secure transmission of customer information

Context​

  • Usage of C# for developing robust and efficient applications
  • Usage of the System library for low-level operating system interactions and utilities.
  • Usage of System.Net for network communication in .NET development
  • Usage of System.IO for Input and Output operations in .NET development

Description​

Non compliant code​

using System;
using System.Net;
using System.IO;

public class Program
{
    public static void Main(string[] args)
    {
        string url = "http://example.com/api/customer";
        WebRequest request = WebRequest.Create(url);
        WebResponse response = request.GetResponse();
        Stream dataStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();
        Console.WriteLine(responseFromServer);
        reader.Close();
        response.Close();
    }
}

The above code is a simple example of an insecure channel being used to transmit customer information. The URL http://example.com/api/customer is used to create a WebRequest object, which is then used to send a request to the server and receive a response.

The vulnerability lies in the use of HTTP instead of HTTPS. HTTP is an insecure protocol because the data transmitted over HTTP is not encrypted and can be intercepted by attackers. In this case, the customer information being transmitted could be intercepted and read by an attacker.

The WebRequest.GetResponse method is used to get a response from the server. The response is then read using a StreamReader object and the data from the server (in this case, the customer information) is read and printed to the console.

In summary, the vulnerability in this code is the use of an insecure HTTP connection to transmit sensitive customer information. This can lead to the data being intercepted and potentially misused by attackers.

Steps​

  • Replace the insecure HTTP protocol with a secure protocol such as HTTPS.
  • Ensure that the server hosting the API supports HTTPS.
  • Obtain an SSL/TLS certificate for the server's domain.
  • Configure the server to use the SSL/TLS certificate for HTTPS communication.
  • Update the URL in the code to use the secure protocol (https://) instead of the insecure protocol (http://).
  • Rebuild and redeploy the application with the updated code.
  • Test the application to verify that customer information is now transmitted over a secure channel.

Compliant code​

using System;
using System.Net;
using System.IO;

public class Program
{
    public static void Main(string[] args)
    {
        string url = "https://example.com/api/customer"; // Changed from http to https
        WebRequest request = WebRequest.Create(url);
        WebResponse response = request.GetResponse();
        Stream dataStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();
        Console.WriteLine(responseFromServer);
        reader.Close();
        response.Close();
    }
}

The original code was vulnerable because it was using an insecure HTTP protocol to transmit customer information. This could potentially expose sensitive customer data to unauthorized parties.

The updated code now uses the secure HTTPS protocol to transmit customer information. This ensures that the data is encrypted during transmission, protecting it from interception by unauthorized parties.

The server hosting the API must support HTTPS and have a valid SSL/TLS certificate for the domain. The server should be configured to use this certificate for HTTPS communication.

After updating the code, the application should be rebuilt and redeployed. Finally, the application should be tested to verify that customer information is now transmitted over a secure channel.

References​

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