[Security-news] SA-CONTRIB-2013-096 - Entity reference - Access bypass

[security-news at drupal.org]

View online: https://drupal.org/node/2140237

   * Advisory ID: DRUPAL-SA-CONTRIB-2013-096
   * Project: Entity reference [1] (third-party module)
   * Version: 7.x
   * Date: 2013-November-20
   * Security risk: Not critical [2]
   * Exploitable from: Remote
   * Vulnerability: Access bypass

-------- DESCRIPTION
---------------------------------------------------------

By default, with an autoselect or a select widget, a user cannot autocomplete
an entity title, nor can they select an entity that they have no access to.
This will correctly throw a 'invalid id' error and does not show the title of
the entity.

However, if a user (A) that has access to the referenced entity (Node 1),
makes that reference on a node (Node 2), and gives edit access to another
user (B), user B will be able to see the node title for the referenced node
(Node 2).

This vulnerability is mitigated by the fact that an attacker must get a user
with access to a private node to reference it via another node that attacker
has edit access to. No other node information is leaked other than the title.


-------- CVE IDENTIFIER(S) ISSUED
--------------------------------------------

   * /A CVE identifier [3] will be requested, and added upon issuance, in
     accordance with Drupal Security Team processes./

-------- VERSIONS AFFECTED
---------------------------------------------------

   * Entityreference 7.x-1.x versions prior to 7.x-1.1-rc1

Drupal core is not affected. If you do not use the contributed Entity
reference [4] module, there is nothing you need to do.

-------- SOLUTION
------------------------------------------------------------

Install the latest version:

   * If you use the Entityreference module for Drupal 7.x, upgrade to
     Entityreference 7.x-1.1 [5]

Also see the Entity reference [6] project page.

-------- REPORTED BY
---------------------------------------------------------

   * Jakob Perry [7]

-------- FIXED BY
------------------------------------------------------------

   * Damien Tournoud [8] the module maintainer
   * Jakob Perry [9]
   * Amitai Burstein [10]

-------- COORDINATED BY
------------------------------------------------------

   * David Stoline [11] and Greg Knaddison [12] of the Drupal Security Team

-------- CONTACT AND MORE INFORMATION
----------------------------------------

The Drupal security team can be reached at security at drupal.org or via the
contact form at http://drupal.org/contact [13].

Learn more about the Drupal Security team and their policies [14], writing
secure code for Drupal [15], and securing your site [16].


[1] http://drupal.org/project/entityreference
[2] http://drupal.org/security-team/risk-levels
[3] http://cve.mitre.org/
[4] http://drupal.org/project/entityreference
[5] https://drupal.org/node/2140229
[6] http://drupal.org/project/entityreference
[7] https://drupal.org/user/45640
[8] http://drupal.org/user/22211
[9] http://drupal.org/user/45640
[10] http://drupal.org/user/57511
[11] https://drupal.org/user/329570
[12] https://drupal.org/user/36762
[13] http://drupal.org/contact
[14] http://drupal.org/security-team
[15] http://drupal.org/writing-secure-code
[16] http://drupal.org/security/secure-configuration