# CVE-2018-0821: Windows AppContainer Elevation Of Privilege Vulnerability

CVE-2018-0821 is fixed in 13 products on 1 platform, first by KB4074591, released February 13, 2018. It is not reported as exploited, but the vendor rates exploitation more likely. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2018-0821
- Priority: Urgent
- CVSS: 5.3 (Important)
- EPSS: 0.0230
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation More Likely
- Published: Feb 13, 2018
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-0821

## Description

<p>An elevation of privilege vulnerability exists when AppContainer improperly implements constrained impersonation.  An attacker who successfully exploited this vulnerability could run processes in an elevated context.</p> <p>To exploit the vulnerability, an attacker would first have to log on to the system, and then run a specially crafted application to take control over the affected system.</p> <p>The security update addresses the vulnerability by correcting how AppContainer implements constrained impersonation.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 1511 for 32-bit Systems | 10586.1417 | [KB4074591](https://patchblox.com/security/data/fix/microsoft/kb4074591.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1511 for x64-based Systems | 10586.1417 | [KB4074591](https://patchblox.com/security/data/fix/microsoft/kb4074591.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.2068 | [KB4074590](https://patchblox.com/security/data/fix/microsoft/kb4074590.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.2068 | [KB4074590](https://patchblox.com/security/data/fix/microsoft/kb4074590.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.909 | [KB4074592](https://patchblox.com/security/data/fix/microsoft/kb4074592.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.909 | [KB4074592](https://patchblox.com/security/data/fix/microsoft/kb4074592.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.248 | [KB4074588](https://patchblox.com/security/data/fix/microsoft/kb4074588.md) | Feb 13, 2018 |
| Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.248 | [KB4074588](https://patchblox.com/security/data/fix/microsoft/kb4074588.md) | Feb 13, 2018 |
| Microsoft | Windows 10 for 32-bit Systems | 10240.17770 | [KB4074596](https://patchblox.com/security/data/fix/microsoft/kb4074596.md) | Feb 13, 2018 |
| Microsoft | Windows 10 for x64-based Systems | 10240.17770 | [KB4074596](https://patchblox.com/security/data/fix/microsoft/kb4074596.md) | Feb 13, 2018 |
| Microsoft | Windows Server 2016 | 14393.2068 | [KB4074590](https://patchblox.com/security/data/fix/microsoft/kb4074590.md) | Feb 13, 2018 |
| Microsoft | Windows Server 2016 (Server Core installation) | 14393.2068 | [KB4074590](https://patchblox.com/security/data/fix/microsoft/kb4074590.md) | Feb 13, 2018 |
| Microsoft | Windows Server, version 1709  (Server Core Installation) | 16299.248 | [KB4074588](https://patchblox.com/security/data/fix/microsoft/kb4074588.md) | Feb 13, 2018 |

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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

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