3 files changed, 29 insertions, 0 deletions
diff --git a/changelogs/unreleased/patch-rdoc-xss.yml b/changelogs/unreleased/patch-rdoc-xss.yml
new file mode 100644
index 00000000000..b428f5435e3
--- /dev/null
+++ b/changelogs/unreleased/patch-rdoc-xss.yml
@@ -0,0 +1,4 @@
+---
+title: Patch XSS vulnerability in RDOC support
+merge_request:
+author:
diff --git a/lib/gitlab/other_markup.rb b/lib/gitlab/other_markup.rb
index 4e2f8ed5587..e67acf28c94 100644
--- a/lib/gitlab/other_markup.rb
+++ b/lib/gitlab/other_markup.rb
@@ -17,6 +17,9 @@ module Gitlab
 
       html = Banzai.post_process(html, context)
 
+      filter = Banzai::Filter::SanitizationFilter.new(html)
+      html = filter.call.to_s
+
       html.html_safe
     end
   end
diff --git a/spec/lib/gitlab/other_markup.rb b/spec/lib/gitlab/other_markup.rb
new file mode 100644
index 00000000000..8f5a353b381
--- /dev/null
+++ b/spec/lib/gitlab/other_markup.rb
@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe Gitlab::OtherMarkup, lib: true do
+  context "XSS Checks" do
+    links = {
+      'links' => {
+        file: 'file.rdoc',
+        input: 'XSS[JaVaScriPt:alert(1)]',
+        output: '<p><a>XSS</a></p>'
+      }
+    }
+    links.each do |name, data|
+      it "does not convert dangerous #{name} into HTML" do
+        expect(render(data[:file], data[:input], context)).to eql data[:output]
+      end
+    end
+  end
+
+  def render(*args)
+    described_class.render(*args)
+  end
+end