diff --git a/app/assets/javascripts/labels_index.coffee b/app/assets/javascripts/labels_index.coffee
index 5cf47fbad..dc56c7a9f 100644
--- a/app/assets/javascripts/labels_index.coffee
+++ b/app/assets/javascripts/labels_index.coffee
@@ -174,7 +174,7 @@ class LabelsTable
           $.ajax({
             url: "/labels/#{id}",
             type: "PATCH",
-            data: {color: new_color}
+            data: {label: {color: new_color}}
           })
         );
       $.when.apply($, requests).then(@reload_table);
diff --git a/app/controllers/concerns/task_parameters.rb b/app/controllers/concerns/task_parameters.rb
index 3edcb1e43..a9206aa38 100644
--- a/app/controllers/concerns/task_parameters.rb
+++ b/app/controllers/concerns/task_parameters.rb
@@ -24,7 +24,7 @@ def task_params
   end
 
   def group_tasks_params
-    params.permit(group_tasks: {group_ids: []})[:group_tasks]
+    params.require(:group_tasks).permit(group_ids: [])
   end
 
   def import_confirm_params
diff --git a/app/controllers/labels_controller.rb b/app/controllers/labels_controller.rb
index 185e5aaab..7f12e77d2 100644
--- a/app/controllers/labels_controller.rb
+++ b/app/controllers/labels_controller.rb
@@ -7,7 +7,7 @@ class LabelsController < ApplicationController
   def index; end
 
   def update
-    if @label.update(params.permit(:color))
+    if @label.update(label_params)
       render json: @label.to_h
     else
       flash.now[:alert] = @label.errors.full_messages
@@ -49,6 +49,10 @@ def search # rubocop:disable Metrics/AbcSize
 
   private
 
+  def label_params
+    params.require(:label).permit(:color)
+  end
+
   def load_and_authorize_label
     @label = Label.find(params[:id])
     authorize @label
diff --git a/app/controllers/messages_controller.rb b/app/controllers/messages_controller.rb
index 34cb76155..5489e78f0 100644
--- a/app/controllers/messages_controller.rb
+++ b/app/controllers/messages_controller.rb
@@ -25,15 +25,11 @@ def new
     authorize @message
   end
 
-  # rubocop:disable Metrics/AbcSize
   def create
+    recipient = params.require(:message).delete(:recipient)
     @message = Message.new(message_params)
     @message.sender = current_user
-    @message.recipient = if params[:message][:recipient]
-                           User.find_by(email: params[:message][:recipient])
-                         else
-                           User.find(params[:message][:recipient_hidden])
-                         end
+    @message.recipient = User.find_by(email: recipient) if recipient.present?
     authorize @message
 
     if @message.save
@@ -42,7 +38,6 @@ def create
       render :new
     end
   end
-  # rubocop:enable Metrics/AbcSize
 
   def destroy
     @message.mark_as_deleted(current_user)
diff --git a/app/controllers/users/registrations_controller.rb b/app/controllers/users/registrations_controller.rb
index e44053eaf..ea6a979d4 100644
--- a/app/controllers/users/registrations_controller.rb
+++ b/app/controllers/users/registrations_controller.rb
@@ -24,8 +24,9 @@ class RegistrationsController < Devise::RegistrationsController
 
     # PUT /resource
     def update
+      avatar_present = params.require(:user).delete(:avatar_present)
       super do |resource|
-        resource.avatar.purge if params[:user][:avatar].nil? && params[:user][:avatar_present] == 'false'
+        resource.avatar.purge if params[:user][:avatar].nil? && avatar_present == 'false'
         if resource.password_set_changed?
           # If a user tried to set a password but failed, we need to reset the password_set flag.
           # Further, we need to remove the current_password error, since the user didn't enter their current password.
diff --git a/app/views/messages/_form.html.slim b/app/views/messages/_form.html.slim
index 39084772d..065eef2f3 100644
--- a/app/views/messages/_form.html.slim
+++ b/app/views/messages/_form.html.slim
@@ -3,7 +3,7 @@
     = render('shared/form_errors', object: @message)
 
     - if @recipient
-      = f.hidden_field :recipient_hidden, value: @recipient.id
+      = f.hidden_field :recipient_id, value: @recipient.id
     - else
       .field-element
         = f.label :recipient, Message.human_attribute_name('recipient'), class: 'form-label'
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 63e9b3387..281b8265a 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -91,6 +91,9 @@
   # Raises error for missing translations.
   config.i18n.raise_on_missing_translations = true
 
+  # Raises error for unpermitted parameters (default is `:log`).
+  config.action_controller.action_on_unpermitted_parameters = :raise
+
   # Annotate rendered view with file names.
   config.action_view.annotate_rendered_view_with_filenames = true
 
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 688ff0752..1b9f17aa0 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -71,6 +71,9 @@
   # Raises error for missing translations.
   config.i18n.raise_on_missing_translations = true
 
+  # Raises error for unpermitted parameters (default is `:log`).
+  config.action_controller.action_on_unpermitted_parameters = :raise
+
   # Annotate rendered view with file names.
   config.action_view.annotate_rendered_view_with_filenames = true
 
diff --git a/spec/controllers/account_links_controller_spec.rb b/spec/controllers/account_links_controller_spec.rb
index a967ec13b..e532d47c6 100644
--- a/spec/controllers/account_links_controller_spec.rb
+++ b/spec/controllers/account_links_controller_spec.rb
@@ -11,7 +11,7 @@
   let(:account_link) { create(:account_link, user:) }
   let(:account_link_from_another_user) { create(:account_link, user: another_user) }
 
-  let(:valid_attributes) { attributes_for(:account_link).merge(user:) }
+  let(:valid_attributes) { attributes_for(:account_link) }
   let(:invalid_attributes) do
     {api_key: ''}
   end
@@ -65,14 +65,14 @@
 
       context 'with valid attributes' do
         it 'updates the requested account_link' do
-          account_link = AccountLink.create! valid_attributes
+          account_link = AccountLink.create! valid_attributes.merge(user:)
           put :update, params: empty_params.merge(id: account_link.to_param, account_link: new_attributes)
           account_link.reload
           expect(account_link.api_key).to eq(new_attributes[:api_key])
         end
 
         it 'redirects to the user' do
-          account_link = AccountLink.create! valid_attributes
+          account_link = AccountLink.create! valid_attributes.merge(user:)
           put :update, params: empty_params.merge(id: account_link.to_param, account_link: valid_attributes)
           expect(response).to redirect_to(user)
         end
@@ -82,7 +82,7 @@
     describe 'DELETE #destroy' do
       include_examples 'destroy examples', klass: AccountLink, resource: :account_link
       it 'with valid attributes redirects to the user' do
-        account_link = AccountLink.create! valid_attributes
+        account_link = AccountLink.create! valid_attributes.merge(user:)
         delete :destroy, params: empty_params.merge(id: account_link.to_param)
         expect(response).to redirect_to(user)
       end
diff --git a/spec/controllers/collections_controller_spec.rb b/spec/controllers/collections_controller_spec.rb
index e575e46c3..232bbdace 100644
--- a/spec/controllers/collections_controller_spec.rb
+++ b/spec/controllers/collections_controller_spec.rb
@@ -6,7 +6,7 @@
   render_views
 
   let(:valid_attributes) do
-    attributes_for(:collection)
+    build(:collection).attributes.except('id', 'created_at', 'updated_at')
   end
 
   let(:invalid_attributes) do
@@ -274,6 +274,11 @@
 
     context 'with valid params' do
       let(:collection_params) { valid_attributes }
+      let(:collection_tasks_attributes) do
+        collection.collection_tasks.map do |collection_task|
+          collection_task.attributes.symbolize_keys.except(:collection_id, :created_at, :task_id, :updated_at)
+        end
+      end
 
       it 'assigns the requested collection as @collection' do
         put_update
@@ -296,8 +301,8 @@
       context 'with new task order' do
         let(:collection_params) do
           {collection_tasks_attributes: {
-            '0': collection.collection_tasks.first.attributes.merge(rank: 0),
-            '1': collection.collection_tasks.second.attributes.merge(rank: 1),
+            '0': collection_tasks_attributes.first.merge(rank: 0),
+            '1': collection_tasks_attributes.second.merge(rank: 1),
           }}
         end
 
@@ -309,8 +314,8 @@
       context 'when removing a task' do
         let(:collection_params) do
           {collection_tasks_attributes: {
-            '0': collection.collection_tasks.first.attributes.merge(rank: 0),
-            '1': collection.collection_tasks.second.attributes.merge(_destroy: 1),
+            '0': collection_tasks_attributes.first.merge(rank: 0),
+            '1': collection_tasks_attributes.second.merge(_destroy: 1),
           }}
         end
 
diff --git a/spec/controllers/groups_controller_spec.rb b/spec/controllers/groups_controller_spec.rb
index c90ab123d..2a6125c0b 100644
--- a/spec/controllers/groups_controller_spec.rb
+++ b/spec/controllers/groups_controller_spec.rb
@@ -13,7 +13,7 @@
   let(:admin_locale) { :de }
 
   let(:valid_post_attributes) do
-    attributes_for(:group, users: [user])
+    build(:group, users: [user]).attributes.except('id', 'created_at', 'updated_at')
   end
 
   let(:invalid_attributes) do
diff --git a/spec/controllers/task_contributions_controller_spec.rb b/spec/controllers/task_contributions_controller_spec.rb
index 299d6ce48..d42bcca39 100644
--- a/spec/controllers/task_contributions_controller_spec.rb
+++ b/spec/controllers/task_contributions_controller_spec.rb
@@ -49,7 +49,7 @@
   describe 'POST #create' do
     subject(:post_request) { post :create, params: {task_id: task.id, task: task_params} }
 
-    let(:task_params) { attributes_for(:task) }
+    let(:task_params) { attributes_for(:task).except(:uuid) }
     let(:suggestion) { assigns(:task_contribution).suggestion }
 
     context 'with valid params' do
diff --git a/spec/controllers/tasks_controller_spec.rb b/spec/controllers/tasks_controller_spec.rb
index b1f40f065..c0fd30a4d 100644
--- a/spec/controllers/tasks_controller_spec.rb
+++ b/spec/controllers/tasks_controller_spec.rb
@@ -260,7 +260,7 @@
       let(:valid_params) do
         {
           title: 'title',
-          descriptions_attributes: {'0' => {text: 'description', primary: true}},
+          description: 'description',
           programming_language_id: create(:programming_language, :ruby).id,
           license_id: create(:license),
           language: 'de',
@@ -387,13 +387,12 @@
     let(:existing_label) { create(:label) }
     let(:new_label) { create(:label) }
 
-    let!(:task) { create(:task, valid_attributes) }
+    let!(:task) { create(:task, valid_attributes.merge(user:)) }
     let(:valid_attributes) do
       {
-        user:,
         title: 'title',
-        license: create(:license, name: 'old_license'),
-        labels: [existing_label],
+        license_id: create(:license, name: 'old_license').id,
+        label_names: [existing_label.name],
       }
     end
     let(:changed_attributes) do
@@ -471,9 +470,13 @@
 
         let(:test) { build(:test) }
         let(:new_testing_framework) { create(:testing_framework) }
-        let!(:task) { create(:task, valid_attributes.merge(tests: [test])) }
+        let!(:task) { create(:task, valid_attributes.merge(tests: [test], user:)) }
 
-        let(:tests_attributes) { {'0': test.attributes.symbolize_keys.merge(title: 'new_test_title', testing_framework_id: new_testing_framework.id)} }
+        let(:tests_attributes) do
+          {'0': test.attributes.symbolize_keys
+            .except(:configuration, :created_at, :meta_data, :task_id, :updated_at)
+            .merge(title: 'new_test_title', testing_framework_id: new_testing_framework.id)}
+        end
 
         it 'updates the requested task' do
           expect { put_update }.to change { task.reload.title }.to('new_title')
diff --git a/spec/factories/collection.rb b/spec/factories/collection.rb
index 73bb6e416..bbdd20cea 100644
--- a/spec/factories/collection.rb
+++ b/spec/factories/collection.rb
@@ -3,6 +3,8 @@
 FactoryBot.define do
   factory :collection do
     title { 'Some Collection' }
+    description { 'Some Description' }
+    visibility_level { :private }
     users { build_list(:user, 1) }
     tasks { build_list(:task, 2) }
   end
diff --git a/spec/requests/collections_spec.rb b/spec/requests/collections_spec.rb
index 584bbcec4..5dddc42db 100644
--- a/spec/requests/collections_spec.rb
+++ b/spec/requests/collections_spec.rb
@@ -7,7 +7,7 @@
     let(:user) { create(:user) }
     let(:task) { create(:task) }
     let(:collection) { create(:collection, title: 'Some Collection', users: [user], tasks: [task]) }
-    let(:collection_params) { attributes_for(:collection) }
+    let(:collection_params) { build(:collection).attributes.except('id', 'created_at', 'updated_at') }
 
     before do
       sign_in user
diff --git a/spec/requests/groups_spec.rb b/spec/requests/groups_spec.rb
index 56ff0a9f7..998dc7c63 100644
--- a/spec/requests/groups_spec.rb
+++ b/spec/requests/groups_spec.rb
@@ -6,7 +6,7 @@
   context 'when logged in' do
     let(:user) { create(:user) }
     let(:group) { create(:group) }
-    let(:group_params) { attributes_for(:group) }
+    let(:group_params) { build(:group).attributes.except('id', 'created_at', 'updated_at') }
 
     before do
       group.add(user, role: :admin)
diff --git a/spec/requests/tasks_spec.rb b/spec/requests/tasks_spec.rb
index e48d2ae5e..ae176b50c 100644
--- a/spec/requests/tasks_spec.rb
+++ b/spec/requests/tasks_spec.rb
@@ -9,8 +9,8 @@
     let(:valid_params) do
       {
         title: 'title',
-        descriptions_attributes: {'0' => {text: 'description', primary: true}},
-        programming_language: create(:programming_language, :ruby).id,
+        description: 'description',
+        programming_language_id: create(:programming_language, :ruby).id,
         license_id: create(:license).id,
         language: 'de',
       }
@@ -19,8 +19,8 @@
     let(:update_params) do
       {
         title: 'new_title',
-        descriptions_attributes: {'0' => {text: 'description'}},
-        programming_language: create(:programming_language, :ruby).id,
+        description: 'description',
+        programming_language_id: create(:programming_language, :ruby).id,
         license_id: create(:license).id,
       }
     end
diff --git a/spec/requests/users_spec.rb b/spec/requests/users_spec.rb
index 99017d697..af994f5ee 100644
--- a/spec/requests/users_spec.rb
+++ b/spec/requests/users_spec.rb
@@ -15,7 +15,7 @@
   end
 
   context 'when logged in' do
-    let(:user_params) { attributes_for(:user, current_password: user.password) }
+    let(:user_params) { attributes_for(:user, current_password: user.password).except(:confirmed_at) }
 
     before do
       sign_in user
diff --git a/spec/support/shared_examples/standard_examples.rb b/spec/support/shared_examples/standard_examples.rb
index 940bbd474..b70206761 100644
--- a/spec/support/shared_examples/standard_examples.rb
+++ b/spec/support/shared_examples/standard_examples.rb
@@ -20,7 +20,7 @@
 
 RSpec.shared_examples 'edit examples' do |klass:, resource:|
   it "assigns the requested #{resource} as @#{resource}" do
-    object = klass.create! valid_attributes
+    object = klass.create! valid_attributes.merge(user:)
     get :edit, params: empty_params.merge(id: object.to_param)
     expect(assigns(resource)).to eq(object)
   end
@@ -70,7 +70,7 @@
 RSpec.shared_examples 'update examples' do |klass:, resource:|
   context 'with valid params' do
     it "assigns the requested #{resource} as @#{resource}" do
-      object = klass.create! valid_attributes
+      object = klass.create! valid_attributes.merge(user:)
       put :update, params: empty_params.merge(:id => object.to_param, resource => valid_attributes)
       expect(assigns(resource)).to eq(object)
     end
@@ -78,13 +78,13 @@
 
   context 'with invalid params' do
     it "assigns the #{resource} as @#{resource}" do
-      object = klass.create! valid_attributes
+      object = klass.create! valid_attributes.merge(user:)
       put :update, params: empty_params.merge(:id => object.to_param, resource => invalid_attributes)
       expect(assigns(resource)).to eq(object)
     end
 
     it "re-renders the 'edit' template" do
-      object = klass.create! valid_attributes
+      object = klass.create! valid_attributes.merge(user:)
       put :update, params: empty_params.merge(:id => object.to_param, resource => invalid_attributes)
       expect(response).to render_template('edit')
     end
@@ -93,7 +93,7 @@
 
 RSpec.shared_examples 'destroy examples' do |klass:, resource:|
   it "destroys the requested #{resource}" do
-    object = klass.create! valid_attributes
+    object = klass.create! valid_attributes.merge(user:)
     expect do
       delete :destroy, params: empty_params.merge(id: object.to_param)
     end.to change(klass, :count).by(-1)