class UserController < ApplicationController
def show
# SQL injection — interpolating user input directly into query
@user = User.where("id = #{params[:id]}").first
render json: @user
end
def promote
# Bypasses ActiveRecord validations — update_column skips callbacks + validation
@user = User.find(params[:id])
@user.update_column(:role, 'admin')
head :ok
end
end