Flag – Moderately Critical – Access Bypass – SA-CONTRIB-2016-050

Description

Flag enables users to mark content with any number of admin-defined flags, such as ‘bookmarks’ or ‘spam’. Flag Bookmark is a submodule within Flag, which provides a ‘bookmarks’ flag, and default views to list bookmarked content.

The provided view that lists each user’s bookmarked content as a tab on their user profile has for its access control the permission to use the ‘bookmarks’ flag. This means that any user who has permission to use the ‘bookmarks’ flag can see the list of content that any user has bookmarked.

This vulnerability is mitigated by the fact that the site must have enabled the Flag Bookmark module to create this view, and an attacker must have a role with the permission “Flag node entities as bookmarks”.

CVE identifier(s) issued

  • A CVE identifier will be requested, and added upon issuance, in accordance with Drupal Security Team processes.

Versions affected

  • Flag 7.x-3.x versions prior to 7.x-3.8.

Drupal core is not affected. If you do not use the contributed Flag module, there is nothing you need to do.

Solution

Install the latest version:

  • If you use the Flag module for Drupal 7.x, upgrade to Flag 7.x-3.8

If you have Flag Bookmark enabled, or have enabled it in the past and still have the flag_bookmarks_tab view active, edit this and change the User: uid contextual filter’s as follows:

  1. set the validator to ‘Current user ID matches argument value’
  2. set the action to take if the filter value does not validate to ‘Show “Page not found”‘.

Also see the Flag project page.

Reported by

Fixed by

Coordinated by

Contact and More Information

The Drupal security team can be reached at security at drupal.org or via the contact form at https://www.drupal.org/contact.

Learn more about the Drupal Security team and their policies, writing secure code for Drupal, and securing your site.

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