The Ubuntu Date and Time Indicator (aka indicator-datetime) 13.10.0+13.10.x before 13.10.0+13.10.20131023.2-0ubuntu1.1 does not properly restrict access to Evolution, which allows local users to bypass the greeter screen restrictions by clicking the date.
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.