CVE-2022-2166 (Ruby, published 2022-11-16T01:15Z)
Description: value: Improper Restriction of Excessive Authentication Attempts in GitHub repository mastodon/mastodon prior to 4.0.0.
Severity: nan (CVSS v3 base score: 9.8)
Weakness: CWE-307 \u2014 Improper Restriction of Excessive Authentication Attempts
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame, making it more susceptible to brute force attacks.
Repository: https://github.com/mastodon/mastodon
Files changed:
Gemfile
Gemfile.lock
config/initializers/rack_attack.rb
config/routes.rb
spec/config/initializers/rack_attack_spec.rb
Commit message: Fix rate limiting for paths with formats (#20675)



Vulnerable code:


    req.remote_ip if req.api_request? && req.unauthenticated?
    req.authenticated_user_id if req.post? && req.path.match?('^/api/v\d+/media')
    req.remote_ip if req.path.start_with?('/media_proxy')
    req.remote_ip if req.post? && req.path == '/api/v1/accounts'
    req.remote_ip if req.paging_request? && req.unauthenticated?
  API_DELETE_REBLOG_REGEX = /\A\/api\/v1\/statuses\/[\d]+\/unreblog/.freeze
  API_DELETE_STATUS_REGEX = /\A\/api\/v1\/statuses\/[\d]+/.freeze
    if req.post? && req.path == '/auth'
      addr = req.remote_ip
      addr = IPAddr.new(addr) if addr.is_a?(String)
      addr = addr.mask(64) if addr.ipv6?
      addr.to_s
    end
    req.remote_ip if req.post? && req.path == '/auth/password'
    req.params.dig('user', 'email').presence if req.post? && req.path == '/auth/password'
    req.remote_ip if req.post? && %w(/auth/confirmation /api/v1/emails/confirmations).include?(req.path)
    if req.post? && req.path == '/auth/password'
    req.remote_ip if req.post? && req.path == '/auth/sign_in'
    req.session[:attempt_user_id] || req.params.dig('user', 'email').presence if req.post? && req.path == '/auth/sign_in'
  devise_for :users, path: 'auth', controllers: {
  get '/media_proxy/:id/(*any)', to: 'media_proxy#show', as: :media_proxy
  namespace :api do

Fixed code:
  gem 'rack-test', '~> 2.0'
  rack-test (~> 2.0)
    def throttleable_remote_ip
      @throttleable_remote_ip ||= begin
        ip = IPAddr.new(remote_ip)

        if ip.ipv6?
          ip.mask(64)
        else
          ip
        end
      end.to_s
    end

    def path_matches?(other_path)
      /\A#{Regexp.escape(other_path)}(\..*)?\z/ =~ path
    end

    req.throttleable_remote_ip if req.api_request? && req.unauthenticated?
    req.authenticated_user_id if req.post? && req.path.match?(/\A\/api\/v\d+\/media\z/i)
    req.throttleable_remote_ip if req.path.start_with?('/media_proxy')
    req.throttleable_remote_ip if req.post? && req.path == '/api/v1/accounts'
    req.throttleable_remote_ip if req.paging_request? && req.unauthenticated?
  API_DELETE_REBLOG_REGEX = /\A\/api\/v1\/statuses\/[\d]+\/unreblog\z/.freeze
  API_DELETE_STATUS_REGEX = /\A\/api\/v1\/statuses\/[\d]+\z/.freeze
    req.throttleable_remote_ip if req.post? && req.path_matches?('/auth')
    req.throttleable_remote_ip if req.post? && req.path_matches?('/auth/password')
    req.params.dig('user', 'email').presence if req.post? && req.path_matches?('/auth/password')
    req.throttleable_remote_ip if req.post? && (req.path_matches?('/auth/confirmation') || req.path == '/api/v1/emails/confirmations')
    if req.post? && req.path_matches?('/auth/password')
    req.throttleable_remote_ip if req.post? && req.path_matches?('/auth/sign_in')
    req.session[:attempt_user_id] || req.params.dig('user', 'email').presence if req.post? && req.path_matches?('/auth/sign_in')
  devise_for :users, path: 'auth', format: false, controllers: {
  get '/media_proxy/:id/(*any)', to: 'media_proxy#show', as: :media_proxy, format: false
  namespace :api, format: false do
require 'rails_helper'

describe Rack::Attack do
  include Rack::Test::Methods

  def app
    Rails.application
  end

  shared_examples 'throttled endpoint' do
    context 'when the number of requests is lower than the limit' do
      it 'does not change the request status' do
        limit.times do
          request.call
          expect(last_response.status).to_not eq(429)
        end
      end
    end

    context 'when the number of requests is higher than the limit' do
      it 'returns http too many requests' do
        (limit * 2).times do |i|
          request.call
          expect(last_response.status).to eq(429) if i > limit
        end
      end
    end
  end

  let(:remote_ip) { '1.2.3.5' }

  describe 'throttle excessive sign-up requests by IP address' do
    context 'through the website' do
      let(:limit) { 25 }
      let(:request) { ->() { post path, {}, 'REMOTE_ADDR' => remote_ip } }

      context 'for exact path' do
        let(:path)  { '/auth' }
        it_behaves_like 'throttled endpoint'
      end

      context 'for path with format' do
        let(:path)  { '/auth.html' }
        it_behaves_like 'throttled endpoint'
      end
    end

    context 'through the API' do
      let(:limit) { 5 }
      let(:request) { ->() { post path, {}, 'REMOTE_ADDR' => remote_ip } }

      context 'for exact path' do
        let(:path)  { '/api/v1/accounts' }
        it_behaves_like 'throttled endpoint'
      end

      context 'for path with format' do
        let(:path)  { '/api/v1/accounts.json' }

        it 'returns http not found' do
          request.call
          expect(last_response.status).to eq(404)
        end
      end
    end
  end

  describe 'throttle excessive sign-in requests by IP address' do
    let(:limit) { 25 }
    let(:request) { ->() { post path, {}, 'REMOTE_ADDR' => remote_ip } }

    context 'for exact path' do
      let(:path)  { '/auth/sign_in' }
      it_behaves_like 'throttled endpoint'
    end

    context 'for path with format' do
      let(:path)  { '/auth/sign_in.html' }
      it_behaves_like 'throttled endpoint'
    end
  end
end