CVE-2021-42309: Microsoft SharePoint Server-Side Control Improper Input Validation Remote Code Execution Vulnerability

Published Dec 14, 2021
·
Updated

Microsoft SharePoint Server Remote Code Execution Vulnerability

Other sources

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft SharePoint. Authentication is required to exploit this vulnerability. The specific flaw exists within the handling of server-side controls. An unsafe server-side control can be instantiated if it is specified as a child of a permitted control. An attacker can leverage this vulnerability to execute code in the context of the service account.

ZDI

Affected Software

9 affected componentsFixes available
Microsoft SharePoint Server 2019
Microsoft SharePoint Server Subscription Edition
Microsoft SharePoint Foundation 2013
Microsoft SharePoint
Microsoft SharePoint Enterprise Server=2016
Microsoft SharePoint Foundation=2013-sp1
Microsoft SharePoint Server
Microsoft SharePoint Server=2019
Microsoft SharePoint Enterprise Server 2016

Event History

Dec 14, 2021
CVE Published
via Microsoft·08:00 AM
Data Sourced
via Microsoft·08:00 AM
DescriptionSeverityWeakness
Dec 15, 2021
CVE Published
via MITRE·02:14 PM
Data Sourced
via MITRE·02:14 PM
DescriptionSeverity
Feb 22, 2025
Advisory Published
via ZDI·03:03 PM
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Frequently Asked Questions

1

What is the severity of CVE-2021-42309?

The severity of CVE-2021-42309 is high.

2

How does CVE-2021-42309 affect Microsoft SharePoint?

CVE-2021-42309 allows remote attackers to execute arbitrary code on affected installations of Microsoft SharePoint.

3

What authentication is required to exploit CVE-2021-42309?

Authentication is required to exploit CVE-2021-42309.

4

How can I fix CVE-2021-42309 on Microsoft SharePoint Server 2019?

To fix CVE-2021-42309 on Microsoft SharePoint Server 2019, apply the patch provided by Microsoft: [url].

5

How can I fix CVE-2021-42309 on Microsoft SharePoint Foundation 2013?

To fix CVE-2021-42309 on Microsoft SharePoint Foundation 2013, apply the patch provided by Microsoft: [url].

Contact

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