Clickjacking in Rails with Dynamodb

Clickjacking is a client-side UI redress attack where an invisible or misleading interface element tricks a user into performing an unintended action. In a Ruby on Rails application that uses Amazon DynamoDB as its persistence layer, the risk does not stem from DynamoDB itself, but from how Rails renders views and forms that ultimately cause writes to DynamoDB-backed models. When Rails helpers generate forms without explicit frame-busting or anti-CSRF protections, and those forms submit to DynamoDB-based resources, an attacker can embed the application’s UI in an <iframe> and overlay invisible controls.

Consider a Rails controller that finds a DynamoDB-backed model, such as a profile or settings record, and renders a form to update attributes like preferred_theme or email_notifications. If the view relies on Rails form_with without an explicit target and omits X-Frame-Options or Content-Security-Policy (CSP) headers that disallow framing, the page is embeddable. An attacker can craft a page that loads https://app.example.com/settings/edit inside a transparent iframe, position a benign-looking button over a destructive action (like disabling multi-factor authentication), and rely on the Rails form’s POST to update the DynamoDB item via ActiveModel-based parameter handling.

DynamoDB influences the impact chain in two ways. First, if authorization checks (such as those enforced by a before_action) are incomplete or bypassed via insecure direct object references (IDOR), a forged request can update the authenticated user’s DynamoDB item without proper ownership verification. Second, because Rails abstracts persistence, developers may assume that model-level validations are sufficient, but validation logic that does not explicitly verify the requesting user’s scope can be sidestepped in a clickjacked context. For example, a controller that does current_user.update(profile_params) without confirming that the profile belongs to current_user can be exploited to modify another user’s DynamoDB item if IDOR exists. MiddleBrick’s checks for BOLA/IDOR and Property Authorization help surface these gaps before an attacker can combine them with a clickjacking vector.

Remediation focuses on Rails-side headers, form design, and robust authorization so that DynamoDB operations are only invoked when the request is intentional and properly scoped. Below are concrete patterns and code examples that align with DynamoDB-backed models in Rails.

1. Prevent framing with CSP and X-Frame-Options

Ensure responses include headers that block embedding. In a Rails controller, set a strict CSP frame-ancestors directive and the legacy X-Frame-Options header.

class ApplicationController < ActionController::Base
  before_action :set_security_headers

  private

  def set_security_headers
    response.headers['Content-Security-Policy'] = "default-src 'self'; frame-ancestors 'none';"
    response_headers['X-Frame-Options'] = 'DENY'
  end
end

2. Use form_with with explicit target and authenticity token

Always generate forms that do not rely on top-level browsing context navigation. Use form_with with local: true (or Turbo in Rails 7) and avoid leaving the form susceptible to being submitted inside an invisible frame.

<%= form_with model: @profile, url: profile_path(@profile), local: true do |f| %>
  <div>
    <%= f.label :preferred_theme %>
    <%= f.select :preferred_theme, options_for_select([['Light', 'light'], ['Dark', 'dark']]) %>
  </div>
  <div>
    <%= f.submit 'Save preferences' %>
  </div>
<%= end %>

3. Enforce ownership on every DynamoDB update

Do not rely solely on route-based scoping; re-verify ownership inside the controller action before issuing a DynamoDB update. Below is an example using the AWS SDK for Ruby (v3) where the partition key includes the user ID, and we double-check that the item’s owner matches the current user.

class ProfilesController < ApplicationController
  before_action :set_profile, only: [:edit, :update]
  before_action :authorize_owns_profile, only: [:edit, :update]

  def update
    # Build the update expression safely from permitted params
    update_expr = []
    expression_attr_values = {}
    if params[:profile][:preferred_theme]
      update_expr << 'preferred_theme = :theme'
      expression_attr_values[':theme'] = params[:profile][:preferred_theme]
    end
    # Add more attributes as needed

    dynamodb = Aws::DynamoDB::Client.new(region: 'us-east-1')
    update_expr_str = update_expr.join(', ')
    return head :bad_request if update_expr_str.empty?

    dynamodb.update_item(
      table_name: 'profiles',
      key: { 'user_id' => { s: current_user.user_id } },
      update_expression: "SET #{update_expr_str}",
      expression_attribute_values: expression_attr_values,
      condition_expression: 'user_id = :uid',
      return_values: 'UPDATED_NEW'
    )
    # Handle ConditionalCheckFailedException and other errors appropriately
  rescue Aws::DynamoDB::Errors::ConditionalCheckFailedException
    # Item does not belong to user or condition failed
    redirect_to root_path, alert: 'Not authorized.'
  end

  private

  def set_profile
    dynamodb = Aws::DynamoDB::Client.new(region: 'us-east-1')
    begin
      resp = dynamodb.get_item(
        table_name: 'profiles',
        key: { 'user_id' => { s: params[:id] } }
      )
      @profile = resp.item
    rescue Aws::DynamoDB::Errors::ResourceNotFoundException
      @profile = nil
    end
    redirect_to root_path, alert: 'Profile not found' unless @profile
  end

  def authorize_owns_profile
    # Ensure the profile being edited belongs to current_user
    redirect_to root_path, alert: 'Not authorized' unless @profile && @profile['user_id'] == current_user.user_id
  end

  def profile_params
    params.require(:profile).permit(:preferred_theme, :email_notifications)
  end
end

4. Combine with other protections

Use Rails’ built-in CSRF protection (ensure protect_from_forgery is enabled) and validate all inputs against DynamoDB condition expressions to prevent unintended updates. MiddleBrick’s checks for Authentication, BOLA/IDOR, and Property Authorization are particularly effective at catching missing ownership checks before they can be chained with UI redressing attacks.