diff --git a/app/controllers/auth/passwords_controller.rb b/app/controllers/auth/passwords_controller.rb
index b98bcecd0d..5db2668f72 100644
--- a/app/controllers/auth/passwords_controller.rb
+++ b/app/controllers/auth/passwords_controller.rb
@@ -8,7 +8,10 @@ class Auth::PasswordsController < Devise::PasswordsController
 
   def update
     super do |resource|
-      resource.session_activations.destroy_all if resource.errors.empty?
+      if resource.errors.empty?
+        resource.session_activations.destroy_all
+        resource.forget_me!
+      end
     end
   end
 
diff --git a/app/controllers/auth/registrations_controller.rb b/app/controllers/auth/registrations_controller.rb
index 78feb1631e..d319662486 100644
--- a/app/controllers/auth/registrations_controller.rb
+++ b/app/controllers/auth/registrations_controller.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Auth::RegistrationsController < Devise::RegistrationsController
+  include Devise::Controllers::Rememberable
+
   layout :determine_layout
 
   before_action :set_invite, only: [:new, :create]
@@ -24,7 +26,11 @@ class Auth::RegistrationsController < Devise::RegistrationsController
 
   def update
     super do |resource|
-      resource.clear_other_sessions(current_session.session_id) if resource.saved_change_to_encrypted_password?
+      if resource.saved_change_to_encrypted_password?
+        resource.clear_other_sessions(current_session.session_id)
+        resource.forget_me!
+        remember_me(resource)
+      end
     end
   end
 
diff --git a/app/controllers/home_controller.rb b/app/controllers/home_controller.rb
index e56b0d58dd..568025bb61 100644
--- a/app/controllers/home_controller.rb
+++ b/app/controllers/home_controller.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 class HomeController < ApplicationController
+  before_action :redirect_unauthenticated_to_permalinks!
   before_action :authenticate_user!
   before_action :set_referrer_policy_header
 
@@ -10,7 +11,7 @@ class HomeController < ApplicationController
 
   private
 
-  def authenticate_user!
+  def redirect_unauthenticated_to_permalinks!
     return if user_signed_in?
 
     matches = request.path.match(/\A\/web\/(statuses|accounts)\/([\d]+)\z/)
@@ -35,6 +36,7 @@ class HomeController < ApplicationController
     end
 
     matches = request.path.match(%r{\A/web/timelines/tag/(?<tag>.+)\z})
+
     redirect_to(matches ? tag_path(CGI.unescape(matches[:tag])) : default_redirect_path)
   end
 
diff --git a/app/controllers/media_proxy_controller.rb b/app/controllers/media_proxy_controller.rb
index a8261ec2ba..0b1d09de93 100644
--- a/app/controllers/media_proxy_controller.rb
+++ b/app/controllers/media_proxy_controller.rb
@@ -2,6 +2,7 @@
 
 class MediaProxyController < ApplicationController
   include RoutingHelper
+  include Authorization
 
   skip_before_action :store_current_location
   skip_before_action :require_functional!
@@ -10,12 +11,14 @@ class MediaProxyController < ApplicationController
 
   rescue_from ActiveRecord::RecordInvalid, with: :not_found
   rescue_from Mastodon::UnexpectedResponseError, with: :not_found
+  rescue_from Mastodon::NotPermittedError, with: :not_found
   rescue_from HTTP::TimeoutError, HTTP::ConnectionError, OpenSSL::SSL::SSLError, with: :internal_server_error
 
   def show
     RedisLock.acquire(lock_options) do |lock|
       if lock.acquired?
-        @media_attachment = MediaAttachment.remote.find(params[:id])
+        @media_attachment = MediaAttachment.remote.attached.find(params[:id])
+        authorize @media_attachment.status, :show?
         redownload! if @media_attachment.needs_redownload? && !reject_media?
       else
         raise Mastodon::RaceConditionError
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index deaca7f3bd..1720697702 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -6627,7 +6627,6 @@ noscript {
     padding: 15px;
     padding-bottom: 10px;
     color: $primary-text-color;
-    border-radius: 4px;
     font-size: 14px;
     font-weight: 400;
     border-bottom: 1px solid lighten($ui-base-color, 12%);
diff --git a/chart/Chart.yaml b/chart/Chart.yaml
index f028227e35..783569451d 100644
--- a/chart/Chart.yaml
+++ b/chart/Chart.yaml
@@ -20,7 +20,7 @@ version: 0.1.0
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
-appVersion: 3.1.4
+appVersion: 3.1.5
 
 dependencies:
   - name: elasticsearch
diff --git a/chart/values.yaml.template b/chart/values.yaml.template
index 0710722a67..4a8286d001 100644
--- a/chart/values.yaml.template
+++ b/chart/values.yaml.template
@@ -4,7 +4,7 @@ image:
   repository: tootsuite/mastodon
   pullPolicy: Always
   # https://hub.docker.com/r/tootsuite/mastodon/tags
-  tag: v3.1.4
+  tag: v3.1.5
   # alternatively, use `latest` for the latest release or `edge` for the image
   # built from the most recent commit
   #
diff --git a/config/initializers/rack_attack.rb b/config/initializers/rack_attack.rb
index 9c18816dd8..512db73278 100644
--- a/config/initializers/rack_attack.rb
+++ b/config/initializers/rack_attack.rb
@@ -38,15 +38,6 @@ class Rack::Attack
     end
   end
 
-  PROTECTED_PATHS = %w(
-    /auth/sign_in
-    /auth
-    /auth/password
-    /auth/confirmation
-  ).freeze
-
-  PROTECTED_PATHS_REGEX = Regexp.union(PROTECTED_PATHS.map { |path| /\A#{Regexp.escape(path)}/ })
-
   Rack::Attack.safelist('allow from localhost') do |req|
     req.remote_ip == '127.0.0.1' || req.remote_ip == '::1'
   end
@@ -86,8 +77,32 @@ class Rack::Attack
     req.authenticated_user_id if (req.post? && req.path =~ API_DELETE_REBLOG_REGEX) || (req.delete? && req.path =~ API_DELETE_STATUS_REGEX)
   end
 
-  throttle('protected_paths', limit: 25, period: 5.minutes) do |req|
-    req.remote_ip if req.post? && req.path =~ PROTECTED_PATHS_REGEX
+  throttle('throttle_sign_up_attempts/ip', limit: 25, period: 5.minutes) do |req|
+    req.remote_ip if req.post? && req.path == '/auth'
+  end
+
+  throttle('throttle_password_resets/ip', limit: 25, period: 5.minutes) do |req|
+    req.remote_ip if req.post? && req.path == '/auth/password'
+  end
+
+  throttle('throttle_password_resets/email', limit: 5, period: 30.minutes) do |req|
+    req.params.dig('user', 'email').presence if req.post? && req.path == '/auth/password'
+  end
+
+  throttle('throttle_email_confirmations/ip', limit: 25, period: 5.minutes) do |req|
+    req.remote_ip if req.post? && req.path == '/auth/confirmation'
+  end
+
+  throttle('throttle_email_confirmations/email', limit: 5, period: 30.minutes) do |req|
+    req.params.dig('user', 'email').presence if req.post? && req.path == '/auth/password'
+  end
+
+  throttle('throttle_login_attempts/ip', limit: 25, period: 5.minutes) do |req|
+    req.remote_ip if req.post? && req.path == '/auth/sign_in'
+  end
+
+  throttle('throttle_login_attempts/email', limit: 25, period: 1.hour) do |req|
+    req.session[:attempt_user_id] || req.params.dig('user', 'email').presence if req.post? && req.path == '/auth/sign_in'
   end
 
   self.throttled_response = lambda do |env|
diff --git a/config/initializers/rack_attack_logging.rb b/config/initializers/rack_attack_logging.rb
index c30bd8a643..ab4822e96b 100644
--- a/config/initializers/rack_attack_logging.rb
+++ b/config/initializers/rack_attack_logging.rb
@@ -2,5 +2,6 @@ ActiveSupport::Notifications.subscribe(/rack_attack/) do |_name, _start, _finish
   req = payload[:request]
 
   next unless [:throttle, :blacklist].include? req.env['rack.attack.match_type']
+
   Rails.logger.info("Rate limit hit (#{req.env['rack.attack.match_type']}): #{req.ip} #{req.request_method} #{req.fullpath}")
 end
diff --git a/db/migrate/20200622213645_media_attachment_ids_to_timestamp_ids.rb b/db/migrate/20200622213645_media_attachment_ids_to_timestamp_ids.rb
new file mode 100644
index 0000000000..5c6865b927
--- /dev/null
+++ b/db/migrate/20200622213645_media_attachment_ids_to_timestamp_ids.rb
@@ -0,0 +1,17 @@
+class MediaAttachmentIdsToTimestampIds < ActiveRecord::Migration[5.1]
+  def up
+    # Set up the media_attachments.id column to use our timestamp-based IDs.
+    safety_assured do
+      execute("ALTER TABLE media_attachments ALTER COLUMN id SET DEFAULT timestamp_id('media_attachments')")
+    end
+
+    # Make sure we have a sequence to use.
+    Mastodon::Snowflake.ensure_id_sequences_exist
+  end
+
+  def down
+    execute("LOCK media_attachments")
+    execute("SELECT setval('media_attachments_id_seq', (SELECT MAX(id) FROM media_attachments))")
+    execute("ALTER TABLE media_attachments ALTER COLUMN id SET DEFAULT nextval('media_attachments_id_seq')")
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 2a6e322350..93e9a7cfca 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -481,7 +481,7 @@ ActiveRecord::Schema.define(version: 2020_06_28_133322) do
     t.index ["user_id", "timeline"], name: "index_markers_on_user_id_and_timeline", unique: true
   end
 
-  create_table "media_attachments", force: :cascade do |t|
+  create_table "media_attachments", id: :bigint, default: -> { "timestamp_id('media_attachments'::text)" }, force: :cascade do |t|
     t.bigint "status_id"
     t.string "file_file_name"
     t.string "file_content_type"
diff --git a/lib/paperclip/media_type_spoof_detector_extensions.rb b/lib/paperclip/media_type_spoof_detector_extensions.rb
index 9c05573564..363934d8d1 100644
--- a/lib/paperclip/media_type_spoof_detector_extensions.rb
+++ b/lib/paperclip/media_type_spoof_detector_extensions.rb
@@ -2,8 +2,16 @@
 
 module Paperclip
   module MediaTypeSpoofDetectorExtensions
-    def calculated_content_type
-      @calculated_content_type ||= type_from_mime_magic || type_from_file_command
+    def mapping_override_mismatch?
+      !Array(mapped_content_type).include?(calculated_content_type) && !Array(mapped_content_type).include?(type_from_mime_magic)
+    end
+
+    def calculated_media_type_from_mime_magic
+      @calculated_media_type_from_mime_magic ||= type_from_mime_magic.split('/').first
+    end
+
+    def calculated_type_mismatch?
+      !media_types_from_name.include?(calculated_media_type) && !media_types_from_name.include?(calculated_media_type_from_mime_magic)
     end
 
     def type_from_mime_magic
diff --git a/spec/controllers/media_controller_spec.rb b/spec/controllers/media_controller_spec.rb
index ac44a76f20..2925aed599 100644
--- a/spec/controllers/media_controller_spec.rb
+++ b/spec/controllers/media_controller_spec.rb
@@ -28,9 +28,8 @@ describe MediaController do
     end
 
     it 'raises when not permitted to view' do
-      status = Fabricate(:status)
+      status = Fabricate(:status, visibility: :direct)
       media_attachment = Fabricate(:media_attachment, status: status)
-      allow_any_instance_of(MediaController).to receive(:authorize).and_raise(ActiveRecord::RecordNotFound)
       get :show, params: { id: media_attachment.to_param }
 
       expect(response).to have_http_status(404)
diff --git a/spec/controllers/media_proxy_controller_spec.rb b/spec/controllers/media_proxy_controller_spec.rb
new file mode 100644
index 0000000000..32510cf43d
--- /dev/null
+++ b/spec/controllers/media_proxy_controller_spec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe MediaProxyController do
+  render_views
+
+  before do
+    stub_request(:get, 'http://example.com/attachment.png').to_return(request_fixture('avatar.txt'))
+  end
+
+  describe '#show' do
+    it 'redirects when attached to a status' do
+      status = Fabricate(:status)
+      media_attachment = Fabricate(:media_attachment, status: status, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(302)
+    end
+
+    it 'responds with missing when there is not an attached status' do
+      media_attachment = Fabricate(:media_attachment, status: nil, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(404)
+    end
+
+    it 'raises when id cant be found' do
+      get :show, params: { id: 'missing' }
+
+      expect(response).to have_http_status(404)
+    end
+
+    it 'raises when not permitted to view' do
+      status = Fabricate(:status, visibility: :direct)
+      media_attachment = Fabricate(:media_attachment, status: status, remote_url: 'http://example.com/attachment.png')
+      get :show, params: { id: media_attachment.id }
+
+      expect(response).to have_http_status(404)
+    end
+  end
+end