The Swiss Cheese Model

BeyondTrust, December 20th, 2010

We’ve heard a lot of stories from administrators on how they tried implementing a least privileged model without a solution like PowerBroker Desktops.
swiss cheese
Some folks used scripts to grant/remove administrator rights to the user; others used native settings like Group Policy Files system and Registry ACL policies. I am not speaking badly of these admins and admittedly, I have taken similar steps myself in the past; and in moderation these do have a place. The problem with utilizing this approach to completely address Least Privilege or Least-Privileged User Accounts (LUA) is that you get into what we refer to as, ‘The Swiss Cheese Model’. You inherently open up a number of security holes in your enterprise, not to mention risk-breaking compatibility with applications, and create an incredible amount of work maintaining these policies and transferring this knowledge to other administrators. Below is an excerpt taking from a Microsoft KB on this:

Extensive permission changes that are propagated throughout the registry and file system cannot be undone. New folders, such as user profile folders that were not present at the original installation of the operating system, may be affected. Therefore, if you remove a Group Policy setting that performs ACL changes, or you apply the system defaults, you cannot roll back the original ACLs.

Changes to the ACL in the %SystemDrive% folder may cause the following scenarios:

  • The Recycle Bin no longer functions as designed, and files cannot be recovered.
  • A reduction of security that lets a non-administrator view the contents of the administrator’s Recycle Bin.
  • The failure of user profiles to function as expected.
  • A reduction of security that provides interactive users with read access to some or to all user profiles on the system.
  • Performance problems when many ACL edits are loaded into a Group Policy object that includes long logon times or repeated restarts of the target system.
  • Performance problems, including system slowdowns, every 16 hours or so as Group Policy settings are reapplied.
  • Application compatibility problems or application crashes.

In contrast, using BeyondTrust PowerBroker Desktops (FKA Privilege Manager) to facilitate a Least Privileged environment has been proven time and time again to be an effective, easy to use and maintain solution to the issues that arise when going to this type of environment. Using this proven solution has also been the only realistic way to satisfy certain audit requirements that prevent users from running with Administrative Privileges with many of our customers.