Merge branch 'jej-fix-missing-access-check-on-issues' into 'security'

Fix missing access checks on issue lookup using IssuableFinder

Split from !2024 to partially solve https://gitlab.com/gitlab-org/gitlab-ce/issues/23867

:warning: - Potentially untested
:bomb: - No test coverage
:traffic_light: - Test coverage of some sort exists (a test failed when error raised)
:vertical_traffic_light: - Test coverage of return value (a test failed when nil used)
:white_check_mark: - Permissions check tested

- [x] :white_check_mark: app/controllers/projects/branches_controller.rb:39
  - `before_action :authorize_push_code!` helpes limit/prevent exploitation. Always checks for reporter access so fine with
    confidential issues, issues only visible to team, etc.
- [x] :traffic_light: app/models/cycle_analytics/summary.rb:9 [`.count`]
- [x] :white_check_mark: app/controllers/projects/todos_controller.rb:19

- [x] Potential double render in app/controllers/projects/todos_controller.rb

- https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/2024/diffs#cedccb227af9bfdf88802767cb58d43c2b977439_24_24

See merge request !2030

6 files changed, 17 insertions, 13 deletions

diff --git a/app/controllers/projects/branches_controller.rb b/app/controllers/projects/branches_controller.rb
index 6b9f37983c4..89d84809e3a 100644
--- a/app/controllers/projects/branches_controller.rb
+++ b/app/controllers/projects/branches_controller.rb
@@ -36,7 +36,7 @@ class Projects::BranchesController < Projects::ApplicationController
         execute(branch_name, ref)
 
     if params[:issue_iid]
-      issue = @project.issues.find_by(iid: params[:issue_iid])
+      issue = IssuesFinder.new(current_user, project_id: @project.id).find_by(iid: params[:issue_iid])
       SystemNoteService.new_issue_branch(issue, @project, current_user, branch_name) if issue
     end
 
diff --git a/app/controllers/projects/cycle_analytics_controller.rb b/app/controllers/projects/cycle_analytics_controller.rb
index fd263960b93..ac639ef015b 100644
--- a/app/controllers/projects/cycle_analytics_controller.rb
+++ b/app/controllers/projects/cycle_analytics_controller.rb
@@ -6,7 +6,7 @@ class Projects::CycleAnalyticsController < Projects::ApplicationController
   before_action :authorize_read_cycle_analytics!
 
   def show
-    @cycle_analytics = ::CycleAnalytics.new(@project, from: start_date(cycle_analytics_params))
+    @cycle_analytics = ::CycleAnalytics.new(@project, current_user, from: start_date(cycle_analytics_params))
 
     stats_values, cycle_analytics_json = generate_cycle_analytics_data
 
diff --git a/app/controllers/projects/todos_controller.rb b/app/controllers/projects/todos_controller.rb
index 5685d0f4e7c..52517381c65 100644
--- a/app/controllers/projects/todos_controller.rb
+++ b/app/controllers/projects/todos_controller.rb
@@ -16,13 +16,7 @@ class Projects::TodosController < Projects::ApplicationController
     @issuable ||= begin
       case params[:issuable_type]
       when "issue"
-        issue = @project.issues.find(params[:issuable_id])
-
-        if can?(current_user, :read_issue, issue)
-          issue
-        else
-          render_404
-        end
+        IssuesFinder.new(current_user, project_id: @project.id).find(params[:issuable_id])
       when "merge_request"
         @project.merge_requests.find(params[:issuable_id])
       end
diff --git a/app/finders/issuable_finder.rb b/app/finders/issuable_finder.rb
index 612f15cbd70..e42d5afdd89 100644
--- a/app/finders/issuable_finder.rb
+++ b/app/finders/issuable_finder.rb
@@ -43,6 +43,14 @@ class IssuableFinder
     sort(items)
   end
 
+  def find(*params)
+    execute.find(*params)
+  end
+
+  def find_by(*params)
+    execute.find_by(*params)
+  end
+
   def group
     return @group if defined?(@group)
 
diff --git a/app/models/cycle_analytics.rb b/app/models/cycle_analytics.rb
index cb8e088d21d..ba4ee6fcf9d 100644
--- a/app/models/cycle_analytics.rb
+++ b/app/models/cycle_analytics.rb
@@ -1,14 +1,15 @@
 class CycleAnalytics
   STAGES = %i[issue plan code test review staging production].freeze
 
-  def initialize(project, from:)
+  def initialize(project, current_user, from:)
     @project = project
+    @current_user = current_user
     @from = from
     @fetcher = Gitlab::CycleAnalytics::MetricsFetcher.new(project: project, from: from, branch: nil)
   end
 
   def summary
-    @summary ||= Summary.new(@project, from: @from)
+    @summary ||= Summary.new(@project, @current_user, from: @from)
   end
 
   def permissions(user:)
diff --git a/app/models/cycle_analytics/summary.rb b/app/models/cycle_analytics/summary.rb
index b46db449bf3..82f53d17ddd 100644
--- a/app/models/cycle_analytics/summary.rb
+++ b/app/models/cycle_analytics/summary.rb
@@ -1,12 +1,13 @@
 class CycleAnalytics
   class Summary
-    def initialize(project, from:)
+    def initialize(project, current_user, from:)
       @project = project
+      @current_user = current_user
       @from = from
     end
 
     def new_issues
-      @project.issues.created_after(@from).count
+      IssuesFinder.new(@current_user, project_id: @project.id).execute.created_after(@from).count
     end
 
     def commits