Re: [Full-disclosure] [Security-news] SA-CONTRIB-2012-040 - CKEditor and FCKeditor - multiple XSS, arbitrary code execution



Hello MaXe,

Thanks for the feedback.

Our security advisories are meant to be a little opaque and do not
include a POC, so I can understand how these two issues could be
confusing: they both include XSS in something named (F)CKEditor.

However this issue is quite different from the one you identified.

Your advisory was about Javascript execution in html attributes inside
the Javascript/CKEditor tool itself. This vulnerability is about a
feature of the Drupal module written in PHP which responds to Ajax
requests and sends back text filtered using one of Drupal's Input
Formats.

Users of Drupal who upgraded (F)CKEditor Javascript previously to
address the issue you identified in that code need to update their
Drupal module as well to fix the issue described in the advisory
SA-CONTRIB-2012-040.

Regards,
Greg


On Wed, Mar 14, 2012 at 2:42 PM, InterN0T Advisories
<advisories@xxxxxxxxxxxx> wrote:
FYI, this bug was recently fixed by the CKEditor Developers, as the bug
itself was in the CKEditor module, not Drupal. (They just use it like
everyone else.)

Cartoon of the day: http://i.imgur.com/IbRbx.jpg


References:
https://dev.ckeditor.com/ticket/8630#comment:23
http://seclists.org/fulldisclosure/2012/Jan/279
http://forum.intern0t.org/intern0t-advisories/4102-drupal-ckeditor-3-0-3-6-2-persistent-eventhandler-cross-site-scripting.html
http://i.imgur.com/IbRbx.jpg


Best regards,
MaXe

PS: Sorry for the previous HTML e-mail.

On Wed, 14 Mar 2012 19:03:36 +0000 (UTC), security-news@xxxxxxxxxx wrote:
* Advisory ID: DRUPAL-SA-CONTRIB-2012-040
  * Project: CKEditor [1], FCKeditor [2] - WYSIWYG HTML editor
(third-party
    module)
  * Version: 6.x, 7.x
  * Date: 2012-March-14
  * Security risk: Highly critical [3]
  * Exploitable from: Remote
  * Vulnerability: Cross Site Scripting, Cross Site Request Forgery,
  Arbitrary
    PHP code execution

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

CKEditor and its predecessor FCKeditor allow Drupal to replace textarea
fields with the (F)CKEditor - a visual HTML WYSIWYG editor.

The modules have an AJAX callback that filters text to prevent Cross
site
scripting attacks on content edits. This AJAX callback function contains
a
number of bugs which allow attackers to chose which filter to execute on
chosen text or bypass the filter entirely.

The vulnerability can be used to conduct Cross site scripting (XSS)
attacks
on privileged users. Attackers can also execute arbitrary PHP code if
the
core PHP module is enabled. This can happen either directly or by
enticing
a
privileged user to visit a page.

Direct execution of PHP code requires that the attacker has the
following
privileges:

"access fckeditor" for FCKeditor 6.x
"access ckeditor" for CKEditor 6.x

No additional permissions are required to directly exploit the PHP code
execution flaw on CKEditor 7.x.

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

  * FCKeditor 6.x-2.x versions prior to 6.x-2.3.
  * CKEditor 6.x-1.x versions prior to 6.x-1.9.
  * CKEditor 7.x-1.x versions prior to 7.x-1.7.

Drupal core is not affected. If you do not use the contributed CKEditor
-
WYSIWYG HTML editor [4] module, there is nothing you need to do.

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

Install the latest version:

  * If you use the FCKeditor module for Drupal 6.x, upgrade to FCKeditor
    6.x-2.3 [5].
  * If you use the CKEditor module for Drupal 6.x, upgrade to CKEditor
  6.x-1.9
    [6].
  * If you use the CKEditor module for Drupal 7.x, upgrade to CKEditor
  7.x-1.7
    [7].

See also the CKEditor - WYSIWYG HTML editor [8] project page.

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

  * Heine Deelstra [9] of the Drupal Security Team

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

  * Wiktor Walc [10] the module maintainer

-------- 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 [11].

Learn more about the Drupal Security team and their policies [12],
writing
secure code for Drupal [13], and securing your site [14].


[1] http://drupal.org/project/ckeditor
[2] http://drupal.org/project/fckeditor
[3] http://drupal.orgteam/risk-levels
[4] http://drupal.org/project/ckeditor
[5] http://drupal.org/node/1482442
[6] http://drupal.org/node/1482480
[7] http://drupal.org/node/1482466
[8] http://drupal.org/project/ckeditor
[9] http://drupal.org/user/17943
[10] http://drupal.org/user/184556
[11] http://drupal.org/contact
[12] http://drupal.org/security-team
[13] http://drupal.org/writing-secure-code
[14] http://drupal.org/security/secure-configuration

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--
Director Security Services | +1-720-310-5623
Skype: greg.knaddison | http://twitter.com/greggleshttp://acquia.com

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