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By Drupal Security Team on
- Advisory ID: DRUPAL-SA-CONTRIB-2017-073
- Project: CAPTCHA (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
- 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 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 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.
Also see the CAPTCHA project page.
Reported by
Fixed by
- Fabiano Sant'Ana, the module's maintainer.
Coordinated by
- Lee Rowlands of the Drupal Security Team.
- Damien McKenna 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.
Learn more about the Drupal Security team and their policies, writing secure code for Drupal, and securing your site.
Follow the Drupal Security Team on Twitter at https://twitter.com/drupalsecurity
