# CVE-2020-16875: Microsoft Exchange Server Remote Code Execution Vulnerability

CVE-2020-16875 is fixed in 4 products on 1 platform, first by KB4577352, released September 8, 2020. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2020-16875
- Priority: Urgent
- CVSS: 8.4 (Critical)
- EPSS: 0.4650
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Sep 8, 2020
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-16875

## Description

<p>A remote code execution vulnerability exists in Microsoft Exchange server due to improper validation of cmdlet arguments.</p> <p>An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the System user. Exploitation of the vulnerability requires an authenticated user in a certain Exchange role to be compromised.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Exchange handles cmdlet arguments.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 16 |  | [KB4577352](https://patchblox.com/security/data/fix/microsoft/kb4577352.md) | Sep 8, 2020 |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 17 |  | [KB4577352](https://patchblox.com/security/data/fix/microsoft/kb4577352.md) | Sep 8, 2020 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 5 |  | [KB4577352](https://patchblox.com/security/data/fix/microsoft/kb4577352.md) | Sep 8, 2020 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 6 |  | [KB4577352](https://patchblox.com/security/data/fix/microsoft/kb4577352.md) | Sep 8, 2020 |

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Data as of 2026-11-08T06:59:42Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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