Need

Secure generation and transmission of cookies

Context

• Usage of Java for building robust and scalable applications
• Usage of HttpServletRequest for handling HTTP requests in Java Servlets
• Usage of HttpServletResponse for handling HTTP responses in Java Servlets
• Usage of javax.servlet.ServletException for handling servlet exceptions in Java web applications
• Usage of java.io.IOException for handling input/output exceptions in Java
• Usage of javax.servlet.http.Cookie for managing HTTP cookies in Java Servlets

Description

Non compliant code

        import javax.servlet.http.*;

public class CookieController extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Cookie userCookie = new Cookie("user", "admin");
        response.addCookie(userCookie);
    }
}
        
        

In the above code, a cookie named 'user' is being created and its value is set to 'admin'. This cookie is then added to the HTTP response using the response.addCookie(userCookie); method.

The vulnerability lies in the fact that the Secure attribute is not set for this cookie. The Secure attribute ensures that the cookie is only sent over secure (HTTPS) connections. If this attribute is not set, the cookie can be transmitted over any connection, secure or not. This could potentially expose sensitive information contained in the cookie to malicious users if the connection is intercepted.

In this particular case, the 'user' cookie which likely contains sensitive user information does not have the Secure attribute set, and so is vulnerable to being intercepted and read if the connection is insecure.

Steps

• Identify the sensitive cookies that need to be secured.
• Set the Secure attribute for each sensitive cookie.
• Ensure that the cookies are only sent over a secure channel (HTTPS).
• Implement proper session management and authentication mechanisms to protect sensitive data.
• Regularly review and update the cookie security measures to stay up-to-date with best practices.

Compliant code

        import javax.servlet.http.*;

public class CookieController extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Cookie userCookie = new Cookie("user", "admin");
        userCookie.setSecure(true); // Set the Secure attribute
        response.addCookie(userCookie);
    }
}
        
        

The original code was creating a cookie without setting the Secure attribute. This could potentially allow the cookie to be sent over an insecure channel, exposing sensitive information.

The fixed code sets the Secure attribute for the cookie using the setSecure method. This ensures that the cookie will only be sent over a secure channel (HTTPS).

In addition to this, it's important to implement proper session management and authentication mechanisms to further protect sensitive data. Regularly reviewing and updating the cookie security measures to stay up-to-date with best practices is also recommended.

References

• 130. Insecurely generated cookies - Secure