published December 7, 2013
The json rendering functionality in the Context module 6.x-2.x before 6.x-3.2 and 7.x-3.x before 7.x-3.0 for Drupal uses Drupal's token scheme to restrict access to blocks, which makes it easier for remote authenticated users to guess the access token for a block by leveraging the token from a block to which the user has access.