Microsoft Windows Defender Application Control CVE-2019-0733 Security Feature Bypass Vulnerability

Description

A security feature bypass vulnerability exists in Windows Defender Application Control (WDAC) which could allow an attacker to bypass WDAC enforcement. An attacker who successfully exploited this vulnerability could circumvent Windows PowerShell Constrained Language Mode on the machine. To exploit the vulnerability, an attacker would first have to access the local machine, and then place PowerShell into Constrained Language mode. By doing that an attacker could leverage script debugging to abuse signed modules in an unintended way. The update addresses the vulnerability by correcting how PowerShell functions in Constrained Language Mode.

Affected Applications

Windows 10
Windows Server 2016
Windows Server version 1803 (Server Core Installation)
Windows Server 2019
Windows Server version 1903 (Server Core installation)

CVE References

Other References