Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

            A vulnerability has been discovered in Drupal Core
                             5 September 2013


        AusCERT Security Bulletin Summary

Product:           Drupal
Publisher:         Drupal
Operating System:  UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Reduced Security -- Remote/Unauthenticated
Resolution:        Mitigation

Original Bulletin: 

- --------------------------BEGIN INCLUDED TEXT--------------------

PSA-2013-001: Drupal core - Users can insert hidden text and links

View online: https://drupal.org/node/2081887

  * Advisory ID: PSA-2013-001
  * Project: Drupal core [1]
  * Version: 6.x, 7.x
  * Date: 2013-September-04
  * Security risk: Not critical [2]
  * Exploitable from: Remote
  * Vulnerability: Information Disclosure

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

This is a public service announcement regarding possible insertion of hidden
links in comments using core CSS selectors within filtered HTML Text formats
("Input formats" in Drupal 6). Drupal core provides several CSS selectors
that, by design, hide elements on the page. Using these selectors it is
possible to create links to third-party websites that are hidden within a
comment. This technique has been observed on live production websites.

Drupal core provides mechanisms that sanitize user submitted links by adding
a rel="nofollow" attribute. This feature can be enabled for Drupal 7 sites at
admin/config/content/formats/filtered_html and for Drupal 6 sites at
admin/settings/filters/1/configure. Note that these paths are for the default
formats provided with core. Your site may define custom formats which should
be reviewed and updated as well.

Careful moderation of user submitted comments is always advised.
Additionally, automated comment moderation tools may help to mitigate and
flag these malicious comment submissions.

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

Review user-submitted content on your site to see if untrusted users have
posted content that includes classes. Review those classes to see if they
will hide unwanted content.

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

  * Aaron Weiss [3]

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

  * David Stoline [4] 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 [5].

Learn more about the Drupal Security team and their policies [6], writing
secure code for Drupal [7], and securing your site [8].

[1] http://drupal.org/project/drupal
[2] http://drupal.org/security-team/risk-levels
[3] http://drupal.org/user/745366
[4] http://drupal.org/user/329570
[5] http://drupal.org/contact
[6] http://drupal.org/security-team
[7] http://drupal.org/writing-secure-code
[8] http://drupal.org/security/secure-configuration

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:


Australian Computer Emergency Response Team
The University of Queensland
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
Comment: http://www.auscert.org.au/render.html?it=1967