CVE-2021-42321: Microsoft Exchange Server Remote Code Execution Vulnerability

Published Nov 9, 2021
·
Updated

An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.

Other sources

Microsoft Exchange Server Remote Code Execution Vulnerability

Affected Software

9 affected componentsFixes available
Microsoft Exchange
Microsoft Exchange Server=2016-cumulative_update_21
Microsoft Exchange Server=2016-cumulative_update_22
Microsoft Exchange Server=2019-cumulative_update_10
Microsoft Exchange Server=2019-cumulative_update_11
Microsoft Exchange Server 2016=22
15.01.2375.017
Microsoft Exchange Server 2019=10
15.02.0792.019
Microsoft Exchange Server 2019=11
15.02.0986.014
Microsoft Exchange Server 2016=21
15.01.2308.020

Event History

Nov 9, 2021
CVE Published
via Microsoft·08:00 AM
Known Exploited
via Microsoft·08:00 AM
Data Sourced
via Microsoft·08:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·08:00 AM
Affected Software
Updated
via Microsoft·08:00 AM
Description
Nov 10, 2021
CVE Published
via MITRE·12:47 AM
Data Sourced
via MITRE·12:47 AM
DescriptionSeverity
Data Sourced
via NVD·01:19 AM
RemedyDescriptionSeverityAffected Software
Nov 17, 2021
Known Ransomware
via CISA·12:00 AM

Frequently Asked Questions

1

What is CVE-2021-42321?

CVE-2021-42321 is a vulnerability in Microsoft Exchange Server that allows an authenticated attacker to perform remote code execution.

2

How does CVE-2021-42321 affect Microsoft Exchange Server?

CVE-2021-42321 affects Microsoft Exchange Server versions 2016 Cumulative Update 21, 2016 Cumulative Update 22, 2019 Cumulative Update 10, and 2019 Cumulative Update 11.

3

What is the severity of CVE-2021-42321?

CVE-2021-42321 has a severity rating of 8.8 (high).

4

How can an attacker exploit CVE-2021-42321?

An authenticated attacker can exploit CVE-2021-42321 by leveraging improper validation in cmdlet arguments within Microsoft Exchange to perform remote code execution.

5

Is there a fix available for CVE-2021-42321?

Yes, Microsoft has released security updates to address CVE-2021-42321. It is recommended to apply the latest Cumulative Updates for the affected versions of Microsoft Exchange Server.

Contact

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