kde-workspace -- privilege escalation

David Edmundson reports:

KDE workspace configuration module for setting the date and time
has a helper program which runs as root for performing actions.
This is secured with polkit.
This helper takes the name of the ntp utility to run as an
argument. This allows a hacker to run any arbitrary command as root
under the guise of updating the time.
An application can gain root priveledges from an admin user with
either misleading information or no interaction.
On some systems the user will be shown a prompt to change the
time. However, if the system has policykit-desktop-privileges
installed, the datetime helper will be invoked by an admin user
without any prompts.