Bypassing Administrator Protection by Abusing UI Access

Microsoft has discovered a vulnerability in Windows that allows bypassing Administrator Protection, a feature designed to prevent malicious applications from gaining elevated privileges. The root cause lies in how UI Access is implemented, where a process running as a limited user can gain a High integrity level and then compromise any administrator process running on the same desktop. This bypasses the intended security boundary of Administrator Protection. The vulnerability stems from a process called UI Access, which allows a limited user to control a High-integrity process, and a method to bypass the secure application directory check. The issue has been addressed in newer versions of Windows, but older versions remain vulnerable. The core problem is that a process running as a limited user can gain a High integrity level and then compromise any administrator process on the same desktop, circumventing the intended security measures.