From 09d54d1f626163fcc6e282544dfc9939fd3cdfd3 Mon Sep 17 00:00:00 2001 From: Eugen Rochko Date: Thu, 2 Jan 2020 17:14:58 +0100 Subject: [PATCH] Fix uncaught query param encoding errors (#12741) --- .../handle_bad_encoding_middleware.rb | 18 ++++++++++++++++ config/application.rb | 2 ++ config/initializers/rack_attack.rb | 3 --- .../handle_bad_encoding_middleware_spec.rb | 21 +++++++++++++++++++ 4 files changed, 41 insertions(+), 3 deletions(-) create mode 100644 app/middleware/handle_bad_encoding_middleware.rb create mode 100644 spec/middleware/handle_bad_encoding_middleware_spec.rb diff --git a/app/middleware/handle_bad_encoding_middleware.rb b/app/middleware/handle_bad_encoding_middleware.rb new file mode 100644 index 000000000..6fce84b15 --- /dev/null +++ b/app/middleware/handle_bad_encoding_middleware.rb @@ -0,0 +1,18 @@ +# frozen_string_literal: true +# See: https://jamescrisp.org/2018/05/28/fixing-invalid-query-parameters-invalid-encoding-in-a-rails-app/ + +class HandleBadEncodingMiddleware + def initialize(app) + @app = app + end + + def call(env) + begin + Rack::Utils.parse_nested_query(env['QUERY_STRING'].to_s) + rescue Rack::Utils::InvalidParameterError + env['QUERY_STRING'] = '' + end + + @app.call(env) + end +end diff --git a/config/application.rb b/config/application.rb index e1f7ae707..58e59fd51 100644 --- a/config/application.rb +++ b/config/application.rb @@ -7,6 +7,7 @@ require 'rails/all' Bundler.require(*Rails.groups) require_relative '../app/lib/exceptions' +require_relative '../app/middleware/handle_bad_encoding_middleware' require_relative '../lib/paperclip/lazy_thumbnail' require_relative '../lib/paperclip/gif_transcoder' require_relative '../lib/paperclip/video_transcoder' @@ -118,6 +119,7 @@ module Mastodon config.active_job.queue_adapter = :sidekiq + config.middleware.insert_before Rack::Runtime, HandleBadEncodingMiddleware config.middleware.use Rack::Attack config.middleware.use Rack::Deflater diff --git a/config/initializers/rack_attack.rb b/config/initializers/rack_attack.rb index 273cac9ca..3cd7ea3a6 100644 --- a/config/initializers/rack_attack.rb +++ b/config/initializers/rack_attack.rb @@ -46,10 +46,7 @@ class Rack::Attack PROTECTED_PATHS_REGEX = Regexp.union(PROTECTED_PATHS.map { |path| /\A#{Regexp.escape(path)}/ }) - # Always allow requests from localhost - # (blocklist & throttles are skipped) Rack::Attack.safelist('allow from localhost') do |req| - # Requests are allowed if the return value is truthy req.remote_ip == '127.0.0.1' || req.remote_ip == '::1' end diff --git a/spec/middleware/handle_bad_encoding_middleware_spec.rb b/spec/middleware/handle_bad_encoding_middleware_spec.rb new file mode 100644 index 000000000..8c0d24f18 --- /dev/null +++ b/spec/middleware/handle_bad_encoding_middleware_spec.rb @@ -0,0 +1,21 @@ +require 'rails_helper' + +RSpec.describe HandleBadEncodingMiddleware do + let(:app) { double() } + let(:middleware) { HandleBadEncodingMiddleware.new(app) } + + it "request with query string is unchanged" do + expect(app).to receive(:call).with("PATH" => "/some/path", "QUERY_STRING" => "name=fred") + middleware.call("PATH" => "/some/path", "QUERY_STRING" => "name=fred") + end + + it "request with no query string is unchanged" do + expect(app).to receive(:call).with("PATH" => "/some/path") + middleware.call("PATH" => "/some/path") + end + + it "request with invalid encoding in query string drops query string" do + expect(app).to receive(:call).with("QUERY_STRING" => "", "PATH" => "/some/path") + middleware.call("QUERY_STRING" => "q=%2Fsearch%2Fall%Forder%3Ddescending%26page%3D5%26sort%3Dcreated_at", "PATH" => "/some/path") + end +end