Remove ability to revoke active session

Session ID is used as a parameter for the revoke session endpoint but it
should never be included in the HTML as an attacker could obtain it via
XSS.

app/controllers/profiles/active_sessions_controller.rb

@@ -4,13 +4,4 @@ class Profiles::ActiveSessionsController < Profiles::ApplicationController
   def index
     @sessions = ActiveSession.list(current_user).reject(&:is_impersonated)
   end
-
-  def destroy
-    ActiveSession.destroy(current_user, params[:id])
-
-    respond_to do |format|
-      format.html { redirect_to profile_active_sessions_url, status: :found }
-      format.js { head :ok }
-    end
-  end
 end

app/views/profiles/active_sessions/_active_session.html.haml

@@ -23,9 +23,3 @@
       %strong Signed in
       on
       = l(active_session.created_at, format: :short)
-
-  - unless is_current_session
-    .float-right
-      = link_to profile_active_session_path(active_session.session_id), data: { confirm: 'Are you sure? The device will be signed out of GitLab.' }, method: :delete, class: "btn btn-danger prepend-left-10" do
-        %span.sr-only Revoke
-        Revoke

changelogs/unreleased/57534_filter_impersonated_sessions.yml

@@ -0,0 +1,6 @@
+---
+title: Do not display impersonated sessions under active sessions and remove ability
+  to revoke session
+merge_request:
+author:
+type: security

doc/user/profile/active_sessions.md

@@ -4,7 +4,7 @@
 >   in GitLab 10.8.
 
 GitLab lists all devices that have logged into your account. This allows you to
-review the sessions and revoke any of it that you don't recognize.
+review the sessions.
 
 ## Listing all active sessions
 
@@ -12,9 +12,3 @@ review the sessions and revoke any of it that you don't recognize.
 1. Navigate to the **Active Sessions** tab.
 
 ![Active sessions list](img/active_sessions_list.png)
-
-## Revoking a session
-
-1. Navigate to your [profile's](#profile-settings) **Settings > Active Sessions**.
-1. Click on **Revoke** besides a session. The current session cannot be
-   revoked, as this would sign you out of GitLab.

spec/features/profiles/active_sessions_spec.rb

@@ -82,31 +82,4 @@ describe 'Profile > Active Sessions', :clean_gitlab_redis_shared_state do
       expect(page).not_to have_content('Chrome on Windows')
     end
   end
-
-  it 'User can revoke a session', :js, :redis_session_store do
-    Capybara::Session.new(:session1)
-    Capybara::Session.new(:session2)
-
-    # set an additional session in another browser
-    using_session :session2 do
-      gitlab_sign_in(user)
-    end
-
-    using_session :session1 do
-      gitlab_sign_in(user)
-      visit profile_active_sessions_path
-
-      expect(page).to have_link('Revoke', count: 1)
-
-      accept_confirm { click_on 'Revoke' }
-
-      expect(page).not_to have_link('Revoke')
-    end
-
-    using_session :session2 do
-      visit profile_active_sessions_path
-
-      expect(page).to have_content('You need to sign in or sign up before continuing.')
-    end
-  end
 end