# CVE-2019-0733: Windows Defender Application Control Security Feature Bypass Vulnerability CVE-2019-0733 is fixed in 24 products on 1 platform, first by KB4494440, released May 14, 2019. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2019-0733 - Priority: Routine - CVSS: 5.3 (Important) - EPSS: 0.0123 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Vendor exploitability assessment: Exploitation Less Likely - Published: May 21, 2019 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-0733 ## 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.

## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.2969 | [KB4494440](https://patchblox.com/security/data/fix/microsoft/kb4494440.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.2969 | [KB4494440](https://patchblox.com/security/data/fix/microsoft/kb4494440.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1805 | [KB4499181](https://patchblox.com/security/data/fix/microsoft/kb4499181.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1805 | [KB4499181](https://patchblox.com/security/data/fix/microsoft/kb4499181.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.1146 | [KB4499179](https://patchblox.com/security/data/fix/microsoft/kb4499179.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1709 for ARM64-based Systems | 16299.1146 | [KB4499179](https://patchblox.com/security/data/fix/microsoft/kb4499179.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.1146 | [KB4499179](https://patchblox.com/security/data/fix/microsoft/kb4499179.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1803 for 32-bit Systems | 17134.765 | [KB4499167](https://patchblox.com/security/data/fix/microsoft/kb4499167.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1803 for ARM64-based Systems | 17134.765 | [KB4499167](https://patchblox.com/security/data/fix/microsoft/kb4499167.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.765 | [KB4499167](https://patchblox.com/security/data/fix/microsoft/kb4499167.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1809 for 32-bit Systems | 17763.503 | [KB4494441](https://patchblox.com/security/data/fix/microsoft/kb4494441.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1809 for ARM64-based Systems | 17763.503 | [KB4494441](https://patchblox.com/security/data/fix/microsoft/kb4494441.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1809 for x64-based Systems | 17763.503 | [KB4494441](https://patchblox.com/security/data/fix/microsoft/kb4494441.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1903 for 32-bit Systems | | [KB4497936](https://patchblox.com/security/data/fix/microsoft/kb4497936.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1903 for ARM64-based Systems | | [KB4497936](https://patchblox.com/security/data/fix/microsoft/kb4497936.md) | May 14, 2019 | | Microsoft | Windows 10 Version 1903 for x64-based Systems | | [KB4497936](https://patchblox.com/security/data/fix/microsoft/kb4497936.md) | May 14, 2019 | | Microsoft | Windows 10 for 32-bit Systems | 10240.18215 | [KB4499154](https://patchblox.com/security/data/fix/microsoft/kb4499154.md) | May 14, 2019 | | Microsoft | Windows 10 for x64-based Systems | 10240.18215 | [KB4499154](https://patchblox.com/security/data/fix/microsoft/kb4499154.md) | May 14, 2019 | | Microsoft | Windows Server 2016 | 14393.2969 | [KB4494440](https://patchblox.com/security/data/fix/microsoft/kb4494440.md) | May 14, 2019 | | Microsoft | Windows Server 2016 (Server Core installation) | 14393.2969 | [KB4494440](https://patchblox.com/security/data/fix/microsoft/kb4494440.md) | May 14, 2019 | | Microsoft | Windows Server 2019 | 17763.503 | [KB4494441](https://patchblox.com/security/data/fix/microsoft/kb4494441.md) | May 14, 2019 | | Microsoft | Windows Server 2019 (Server Core installation) | 17763.503 | [KB4494441](https://patchblox.com/security/data/fix/microsoft/kb4494441.md) | May 14, 2019 | | Microsoft | Windows Server, version 1803 (Server Core Installation) | 17134.765 | [KB4499167](https://patchblox.com/security/data/fix/microsoft/kb4499167.md) | May 14, 2019 | | Microsoft | Windows Server, version 1903 (Server Core installation) | | [KB4497936](https://patchblox.com/security/data/fix/microsoft/kb4497936.md) | May 14, 2019 | --- Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.