System Status "Read more about this warning" points to non existent docs
There are several places where there is a link to docs. These links still point to http://wiki.civicrm.org/confluence... instead of https://docs.civicrm.org/sysadmin/en/latest/setup/security...
I think the following:
The CiviCRM debug log should not be downloadable Should point to https://docs.civicrm.org/sysadmin/en/latest/setup/security/#the-log-file-should-not-be-accessible
Files in the data directory (.../sites/default/files/civicrm/upload/) should not be downloadable. Should point to https://docs.civicrm.org/sysadmin/en/latest/setup/security/#uploads-should-not-be-accessible
Directory ... should not be browseable via the web. Should point to https://docs.civicrm.org/sysadmin/en/latest/setup/security/#directories-should-not-be-browsable
I think the code is in civicrm/CRM/Utils/Check/Component/Security.php