CVE-2011-2726

An access bypass issue was found in Drupal 7.x before version 7.5. If a
Drupal site has the ability to attach File upload fields to any entity type
in the system or has the ability to point individual File upload fields to
the private file directory in comments, and the parent node is denied
access, non-privileged users can still download the file attached to the
comment if they know or guess its direct URL.
If a Drupal site is using these features on comments, and the parent node is
denied access (either by a node access module or by being unpublished), the
file attached to the comment can still be downloaded by non-privileged users if
they know or guess its direct URL.
This issue affects Drupal 7.x only.

Notes