[Security-news] CAPTCHA - Moderately Critical - Denial of Service - SA-CONTRIB-2017-073

[security-news at drupal.org]

View online: https://www.drupal.org/node/2907137

   * Advisory ID: DRUPAL-SA-CONTRIB-2017-073
   * Project: CAPTCHA [1] (third-party module)
   * Version: 7.x
   * Date: 2017-September-06
   * Security risk: 10/25 ( Moderately Critical)
     AC:Basic/A:None/CI:None/II:None/E:Proof/TD:Default [2]
   * Vulnerability: Denial of Service

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

This module enables you to use various techniques to block automated scripts
/ robots from submitting content to a site, e.g. to block spam comments.

The module doesn't properly store the session ID of visitors who are given a
session which could lead to a Denial of Service attack.

This vulnerability is mitigated by the fact that Drupal does not give a
session to all visitors, especially when used with advanced caching systems
like Varnish.


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

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

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

   * CAPTCHA 7.x-1.x versions prior to 7.x-1.5.

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

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

Install the latest version:

   * If you use the CATPCHA module for Drupal 7.x, upgrade to CAPTCHA 7.x-1.5.
     [5]

Also see the CAPTCHA [6] project page.

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

   * Nightwalker3000 [7]

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

   * Fabiano Sant'Ana [8], the module's maintainer.

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

   * Lee Rowlands [9] of the Drupal Security Team.
   * Damien McKenna [10] 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 https://www.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].

Follow the Drupal Security Team on Twitter at
https://twitter.com/drupalsecurity [15]


[1] https://www.drupal.org/project/captcha
[2] https://www.drupal.org/security-team/risk-levels
[3] http://cve.mitre.org/
[4] https://www.drupal.org/project/captcha
[5] https://www.drupal.org/project/captcha/releases/7.x-1.5
[6] https://www.drupal.org/project/captcha
[7] https://www.drupal.org/u/nightwalker3000
[8] https://www.drupal.org/u/wundow
[9] https://www.drupal.org/u/larowlan
[10] https://www.drupal.org/u/damienmckenna
[11] https://www.drupal.org/contact
[12] https://www.drupal.org/security-team
[13] https://www.drupal.org/writing-secure-code
[14] https://www.drupal.org/security/secure-configuration
[15] https://twitter.com/drupalsecurity