A headline feature introduced in the latest release of Windows 11, 25H2 is Administrator Protection. The goal of this feature is to replace User Account Control (UAC) with a more robust and importantly, securable system to allow a local user to access administrator privileges only when necessary. This blog post will give a brief overview of the new feature, how it works and how it’s different from UAC. I’ll then describe some of the security research I undertook while it was in the insider preview builds on Windows 11. Finally I’ll detail one of the nine separate vulnerabilities that I found to bypass the feature to silently gain full administrator privileges. All the issues that I reported to Microsoft have been fixed, either prior to the feature being officially released (in optional update KB5067036) or as subsequent security bulletins. Note: As of 1st December 2025 the Administrator Protection feature has been disabled by Microsoft while an application compatibility issue is dealt with. The issue is unlikely to be related to anything described in this blog post so the analysis doesn’t change. The Problem Administration Protection is Trying to Solve UAC was introduced in Windows Vista to facilitate granting a user administrator privileges temporarily, while the majority of the user’s processes run with limited privileges. Unfortunately, due to the way it was designed, it was quickly apparent it didn’t represent a hard security boundary, and Microsoft downgraded it to a security feature. This was an important change as it made it no longer a priority to fix bypasses of the UAC which allowed a limited process to silently gain administrator privileges. The main issue with the design of UAC was that both the limited user and the administrator user were the same account just with different sets of groups and privileges. This meant they shared profile resources such as the user directory and registry hive. It was also possible to open an administrators process’ According to Google Project Zero, a headline…
