Windows Vista's Take on Least Privilege

We're all anxiously awaiting Microsoft's official release of the oft-delayed Windows Vista. In the meantime, Microsoft has released several interim builds of the OS, including the full-featured Vista Community Technology Preview (CTP). In this version, we got our first real look at the new security features and tools that Microsoft plans to include in Vista. One of the most fundamental security changes will be the OS's new least-privilege support, embodied in the User Account Control (UAC) feature. In earlier Vista beta releases, UAC was called Least-Privileged User Account.

In my article "Learn to Be Least" (October 2005, InstantDoc ID 47622), I defined least privilege and showed you how to better honor it in Windows XP. The principle of least privilege states that you should give a user or a piece of code only the privileges it needs to do a job—nothing less, and certainly nothing more. Malicious code can do much more harm when it executes in the security context of a highly privileged account, and highly privileged processes can do much more harm when they're compromised or simply buggy. . . .