/usr/lib/ruby/vendor_ruby/action_controller/vendor/ is in ruby-actionpack-2.3 2.3.14-5.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/document.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/node.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/sanitizer.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/selector.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/tokenizer.rb
/usr/lib/ruby/vendor_ruby/action_controller/vendor/html-scanner/html/version.rb