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Insecure functionality - Fingerprint

Need​

Enforce secure and authorized user data updates

Context​

  • Usage of Ruby 2.7 for Ruby programming and development
  • Usage of Rails framework for building web applications

Description​

Non compliant code​

class UsersController < ApplicationController
  def update
    @user = User.find(params[:id])
    @user.update_attributes!(params[:user])
    redirect_to @user
  end
end

The above code represents a typical update action in a Ruby on Rails controller. This code is vulnerable to unsolicited user data updates due to the lack of proper authorization checks.

Here is how the code works:

  1. The update method in the UsersController is invoked when a PUT or PATCH request is made to /users/:id.
  2. The User.find(params[:id]) part of the code fetches the user record with the specified id from the database.
  3. The @user.update_attributes!(params[:user]) line is where the vulnerability lies. This line updates the attributes of the @user object with the parameters sent in the request. If the parameters include attributes that should not be updatable by the user, this could lead to unauthorized data modification.
  4. The redirect_to @user line redirects the user to the show page for the updated user record.

The vulnerability lies in the fact that any user can update any data of any other user just by knowing their id and the attribute they want to change. This is a serious security flaw as it allows for unsolicited data updates.

Steps​

  • Implement proper authentication and authorization mechanisms to ensure that only authorized users can update user data.
  • Validate and sanitize user input to prevent any malicious data from being processed.
  • Use strong parameters to explicitly define the allowed parameters for the update action.
  • Implement input validation to ensure that only valid and expected data is accepted for update.
  • Consider implementing rate limiting or throttling mechanisms to prevent abuse or excessive updates.
  • Regularly update and patch the Ruby on Rails framework and its dependencies to ensure that any security vulnerabilities are addressed.
  • Regularly monitor and review the application logs for any suspicious or unauthorized update activities.
  • Implement secure coding practices and follow the principle of least privilege to minimize the impact of any potential vulnerabilities.

Compliant code​

class UsersController < ApplicationController
  before_action :set_user, only: [:update]
  before_action :authorize_user, only: [:update]

  def update
    if @user.update(user_params)
      redirect_to @user
    else
      render :edit
    end
  end

  private

  def set_user
    @user = User.find(params[:id])
  end

  def authorize_user
    unless @user == current_user
      redirect_to root_path, alert: "You are not authorized to perform this action."
    end
  end

  def user_params
    params.require(:user).permit(:name, :email, :password, :password_confirmation)
  end
end

The updated code now includes several security measures to prevent unsolicited user data updates.

  1. before_action :set_user, only: [:update] - This line sets the user to be updated before the update action is performed. This is done to avoid code duplication and to ensure that the user exists.

  2. before_action :authorize_user, only: [:update] - This line checks if the current user is authorized to update the user data. If not, the user is redirected to the root path with an alert message. This is done to ensure that only authorized users can update user data.

  3. if @user.update(user_params) - This line updates the user data with the permitted parameters only. This is done to prevent mass assignment vulnerabilities.

  4. params.require(:user).permit(:name, :email, :password, :password_confirmation) - This line defines the strong parameters for the update action. Only the permitted parameters are allowed for the update. This is done to prevent mass assignment vulnerabilities and to ensure that only valid and expected data is accepted for update.

  5. The authorize_user method - This method checks if the current user is the same as the user to be updated. If not, the user is redirected to the root path with an alert message. This is done to ensure that only the user themselves can update their own data.

By implementing these measures, the application now prevents unsolicited user data updates, thus fixing the insecure functionality vulnerability.

References​

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