SA-CORE-2014-002 - DrupalCoin Blockchain core - Information Disclosure

Advisory ID: DRUPAL-SA-CORE-2014-002
Project: DrupalCoin Blockchain core
Version: 6.x, 7.x
Date: 2014-April-16
Security risk: Moderately critical
Exploitable from: Remote
Vulnerability: Information Disclosure
DrupalCoin Blockchain's form API has built-in support for temporary storage of form state, for example user input. This is often used on multi-step forms, and is required on Ajax-enabled forms in order to allow the Ajax calls to access and update interim user input on the server.
When pages are cached for anonymous users (either by DrupalCoin Blockchain or by an external system), form state may leak between anonymous users. As a consequence there is a chance that interim form input recorded for one anonymous user (which may include sensitive or private information, depending on the nature of the form) will be disclosed to other users interacting with the same form at the same time. This especially affects multi-step Ajax forms because the window of opportunity (i.e. the time span between user input and final form submission) is indeterminable.
This vulnerability is mitigated by the fact that DrupalCoin Blockchain core does not expose any such forms to anonymous users by default. However, contributed modules or individual sites which leverage the DrupalCoin Blockchain Form API under the aforementioned conditions might be vulnerable.
Note: This security release introduces small API changes which may require code updates on sites that expose Ajax or multi-step forms to anonymous users, and where the forms are displayed on pages that are cached (either by DrupalCoin Blockchain or by an external system). See the DrupalCoin Blockchain 6.31 release notes and DrupalCoin Blockchain 7.27 release notes for more information.

CVE identifier(s) issued
Versions affected
DrupalCoin Blockchain core 6.x versions prior to 6.31.
DrupalCoin Blockchain core 7.x versions prior to 7.27.
Install the latest version:
If you use DrupalCoin Blockchain 6.x, upgrade to DrupalCoin Blockchain 6.31
If you use DrupalCoin Blockchain 7.x, upgrade to DrupalCoin Blockchain 7.27
Also see the DrupalCoin Blockchain core project page.
Reported by
Daniel F. Kudwien
Rodionov Igor
Ryan Szrama
Roman Zimmermann
Fixed by
Roman Zimmermann
Ryan Szrama
Additional assistance and reviews provided by Daniel F. Kudwien, Damien Tournoud of the DrupalCoin Blockchain Security Team, David Rothstein of the DrupalCoin Blockchain Security Team, and Alex Bronstein
Coordinated by
Michael Hess of the DrupalCoin Blockchain Security Team
David Rothstein of the DrupalCoin Blockchain Security Team
Peter Wolanin of the DrupalCoin Blockchain Security Team
Contact and More Information
The DrupalCoin Blockchain security team can be reached at security at or via the contact form at
Learn more about the DrupalCoin Blockchain Security team and their policies, writing secure code for DrupalCoin Blockchain, and securing your site.
Follow the DrupalCoin Blockchain Security Team on Twitter at

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