# CVE-2020-1391: Windows Agent Activation Runtime Information Disclosure Vulnerability

CVE-2020-1391 is fixed in 12 products on 1 platform, first by KB4565483, released July 14, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-1391
- Priority: Routine
- CVSS: 5.5 (Important)
- EPSS: 0.0131
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Jul 14, 2020
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1391

## Description

<p>An information disclosure vulnerability exists when the Windows Agent Activation Runtime (AarSvc) fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise the user’s system.</p> <p>To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application.</p> <p>The update addresses the vulnerability by correcting how the Windows Agent Activation Runtime handles objects in memory.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 1903 for 32-bit Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 1903 for ARM64-based Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 1903 for x64-based Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 1909 for 32-bit Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 1909 for ARM64-based Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 1909 for x64-based Systems |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 2004 for 32-bit Systems | 19041.388 | [KB4565503](https://patchblox.com/security/data/fix/microsoft/kb4565503.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 2004 for ARM64-based Systems | 19041.388 | [KB4565503](https://patchblox.com/security/data/fix/microsoft/kb4565503.md) | Jul 14, 2020 |
| Microsoft | Windows 10 Version 2004 for x64-based Systems | 19041.388 | [KB4565503](https://patchblox.com/security/data/fix/microsoft/kb4565503.md) | Jul 14, 2020 |
| Microsoft | Windows Server, version 1903 (Server Core installation) |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows Server, version 1909 (Server Core installation) |  | [KB4565483](https://patchblox.com/security/data/fix/microsoft/kb4565483.md) | Jul 14, 2020 |
| Microsoft | Windows Server, version 2004 (Server Core installation) | 19041.388 | [KB4565503](https://patchblox.com/security/data/fix/microsoft/kb4565503.md) | Jul 14, 2020 |

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Data as of 2026-11-08T00:53:09Z 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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