# CVE-2020-0692: Microsoft Exchange Server Elevation of Privilege Vulnerability

CVE-2020-0692 is fixed in 5 products on 1 platform, first by KB4536988, released February 11, 2020. 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-2020-0692
- Priority: Urgent
- CVSS: n/a (Important)
- EPSS: 0.0326
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation More Likely
- Published: Feb 11, 2020
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-0692

## Description

<p>An elevation of privilege vulnerability exists in Microsoft Exchange Server. An attacker who successfully exploited this vulnerability could gain the same rights as any other user of the Exchange server. This could allow the attacker to perform activities such as accessing the mailboxes of other users.</p> <p>Exploitation of this vulnerability requires Exchange Web Services (EWS) to be enabled and in use in an affected environment. To exploit the vulnerability, an attacker would need to change parameters in the Security Access Token and forward it to a Microsoft Exchange Server, thereby allowing impersonation of another Exchange user.</p> <p>To address this vulnerability, Microsoft has changed the way EWS handles these tokens.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 |  | [KB4536988](https://patchblox.com/security/data/fix/microsoft/kb4536988.md) | Feb 11, 2020 |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 14 |  | [KB4536987](https://patchblox.com/security/data/fix/microsoft/kb4536987.md) | Feb 11, 2020 |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 15 |  | [KB4536987](https://patchblox.com/security/data/fix/microsoft/kb4536987.md) | Feb 11, 2020 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 3 |  | [KB4536987](https://patchblox.com/security/data/fix/microsoft/kb4536987.md) | Feb 11, 2020 |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 4 |  | [KB4536987](https://patchblox.com/security/data/fix/microsoft/kb4536987.md) | Feb 11, 2020 |

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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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