The Commons Wikis module before 7.x-3.1 for Drupal, as used in the Commons module before 7.x-3.1, does not properly restrict access to groups, which allows remote attackers to post arbitrary content to groups via unspecified vectors.
https://drupal.org/node/1954948
https://drupal.org/node/1954768
https://drupal.org/node/1954766
http://secunia.com/advisories/52795
http://secunia.com/advisories/52766