We are running CiviCRM 4.7.23 + Drupal 7.56.
If we try and access one of our Drupal User Records via the CiviCRM Contact record (View Contact -> Actions -> User Record) we get a 404 "Page not found" error from Drupal.
In trying to debug this, we've noticed that the URL generated by the "User Record" link in CiviCRM is like this:
http://oursite.org/user/XXXX&cid=YYY
Where XXXX is the Drupal User ID and YYY is the CiviCRM Contact ID. If I strip off the &cid=YYY part from the URL, the link works and takes me to the correct User Record.
So, is this a bug, or is our site misconfigured somehow?