Lack of multi-factor authentication - Java

Lack of multi-factor authentication - Java

Need

Implementation of multi-factor authentication for critical services

Context

  • Usage of Java 8 for developing applications with enhanced features and performance
  • Usage of javax.servlet-api for Java Servlet development

Description

Non compliant code

        import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        if (isValidUser(username, password)) {
            request.getSession().setAttribute("user", username);
            response.sendRedirect("/home");
        } else {
            response.sendRedirect("/login");
        }
    }

    private boolean isValidUser(String username, String password) {
        // Code to validate user credentials
        // This is just a placeholder
        return username.equals("admin") && password.equals("password");
    }
}

The above code represents a simple login servlet in a Java web application using the javax.servlet package. The servlet receives a POST request with a username and password, validates the credentials, and if they're valid, it sets a session attribute "user" with the value of the username and redirects the user to a home page.

The vulnerability here is the lack of multi-factor authentication. The system only validates the user based on the username and password. If an attacker compromises a user's account, they can easily access the system's resources because there is no second layer of security to verify the user's identity.

In the doPost method, the servlet retrieves the username and password from the request parameters. It then calls the isValidUser method, which checks if the provided credentials match a predefined username and password. If the credentials are valid, the servlet sets a session attribute "user" and redirects the user to a home page. If not, it redirects the user back to the login page.

This approach is vulnerable because it relies solely on something the user knows (username and password). If these credentials are compromised, an attacker can gain access to the system. Implementing multi-factor authentication would add an additional layer of security by also requiring something the user has (like a mobile device to receive a verification code) or something the user is (like a fingerprint or other biometric data).

Steps

  • Implement a multi-factor authentication mechanism for critical services
  • Require users to provide additional authentication factors, such as a one-time password (OTP), biometric data, or hardware tokens
  • Use a secure and reliable authentication method, such as two-factor authentication (2FA) or multi-step verification
  • Ensure that the multi-factor authentication is enforced for all access to critical services, including databases, shared resources, and web services
  • Regularly review and update the multi-factor authentication mechanism to address any emerging vulnerabilities or weaknesses
  • Educate users about the importance of multi-factor authentication and encourage them to enable it for their accounts
  • Monitor and log all authentication attempts to detect any suspicious activity or unauthorized access attempts
  • Implement account lockout mechanisms to prevent brute-force attacks on user accounts
  • Regularly test the multi-factor authentication mechanism to ensure its effectiveness and identify any potential vulnerabilities

Compliant code

        import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String otp = request.getParameter("otp");

        if (isValidUser(username, password) && isValidOTP(username, otp)) {
            request.getSession().setAttribute("user", username);
            response.sendRedirect("/home");
        } else {
            response.sendRedirect("/login");
        }
    }

    private boolean isValidUser(String username, String password) {
        // Code to validate user credentials
        // This is just a placeholder
        return username.equals("admin") && password.equals("password");
    }

    private boolean isValidOTP(String username, String otp) {
        // Code to validate OTP
        // This is just a placeholder
        return otp.equals("123456");
    }
}

The updated code now includes a multi-factor authentication mechanism. In addition to the username and password, the user is now required to enter a one-time password (OTP) as an additional authentication factor.

The doPost method now retrieves the OTP from the request parameters. The isValidUser method checks if the username and password are valid, and the isValidOTP method checks if the OTP is valid.

The user is only authenticated and redirected to the home page if both the username/password and the OTP are valid. If either the username/password or the OTP is invalid, the user is redirected back to the login page.

Please note that the isValidUser and isValidOTP methods in this example are placeholders. In a real-world application, these methods should securely validate the user credentials and OTP against a secure data source, such as a database or an authentication server.

This multi-factor authentication mechanism significantly enhances the security of the system by requiring users to provide multiple forms of verification. This makes it much more difficult for an attacker to gain unauthorized access to the system, even if they have compromised a user's username and password.

References