Acquia Drupal 1.2.55 (Drupal 6.30 core from Pressflow) contains the following updates:

Resolved security alert
* SA-CORE-2013-003 - Drupal core - Multiple vulnerabilities (https://drupal.org/SA-CORE-2014-001)

Drupal core and module updates
* Updated Drupal core to version 6.30 (http://drupal.org/drupal-6.30-release-notes)