Validate zoom links to start with https only

app/validators/zoom_url_validator.rb

@@ -5,8 +5,13 @@
 # Custom validator for zoom urls
 #
 class ZoomUrlValidator < ActiveModel::EachValidator
+  ALLOWED_SCHEMES = %w(https).freeze
+
   def validate_each(record, attribute, value)
-    return if Gitlab::ZoomLinkExtractor.new(value).links.size == 1
+    links_count = Gitlab::ZoomLinkExtractor.new(value).links.size
+    valid = Gitlab::UrlSanitizer.valid?(value, allowed_schemes: ALLOWED_SCHEMES)
+
+    return if links_count == 1 && valid
 
     record.errors.add(:url, 'must contain one valid Zoom URL')
   end

changelogs/unreleased/security-project-import-zoom-xss.yml

+---
+title: Validate zoom links to start with https only
+merge_request: 1055
+author:
+type: security

spec/validators/zoom_url_validator_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ZoomUrlValidator do
+  let(:zoom_meeting) { build(:zoom_meeting) }
+
+  describe 'validations' do
+    context 'when zoom link starts with https' do
+      it 'passes validation' do
+        zoom_meeting.url = 'https://zoom.us/j/123456789'
+
+        expect(zoom_meeting.valid?).to eq(true)
+        expect(zoom_meeting.errors).to be_empty
+      end
+    end
+
+    shared_examples 'zoom link does not start with https' do |url|
+      it 'fails validation' do
+        zoom_meeting.url = url
+        expect(zoom_meeting.valid?).to eq(false)
+
+        expect(zoom_meeting.errors).to be_present
+        expect(zoom_meeting.errors.first[1]).to eq 'must contain one valid Zoom URL'
+      end
+    end
+
+    context 'when zoom link does not start with https' do
+      include_examples 'zoom link does not start with https', 'http://zoom.us/j/123456789'
+
+      context 'when zoom link does not start with a scheme' do
+        include_examples 'zoom link does not start with https', 'testinghttp://zoom.us/j/123456789'
+      end
+    end
+  end
+end