Cross-site scripting (XSS) vulnerability in the Context module before 6.x-2.0-rc4 for Drupal allows remote authenticated users, with Administer Blocks privileges, to inject arbitrary web script or HTML via a block description.

The Context module 6.x-3.x before 6.x-3.1 and 7.x-3.x before 7.x-3.0-beta6 for Drupal does not properly restrict access to block content, which allows remote attackers to obtain sensitive information via a crafted request.

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.

The _json_decode function in plugins/context_reaction_block.inc 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, when using a version of PHP that does not support the json_decode function, allows remote attackers to execute arbitrary PHP code via unspecified vectors related to Ajax operations, possibly involving eval injection.