CVE-2021-24066Network attack vector

Authenticated code execution via workflow deserialization

Published Feb 25, 2021 · Updated Aug 3, 2024

Deserialization of untrusted data in Microsoft SharePoint allows remote authenticated users to execute arbitrary code through workflows. SPWorkflowDataSourceView fails to validate user-supplied data before deserializing it. Authentication is required, and successful exploitation runs code in the SharePoint service context at high integrity.

CVSS severity8.8
High
EPSS probability6.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in Microsoft SharePoint allows remote authenticated users to execute arbitrary code through workflows. SPWorkflowDataSourceView fails to validate user-supplied data before deserializing it. Authentication is required, and successful exploitation runs code in the SharePoint service context at high integrity.

The record

CVE
CVE-2021-24066
Published
Feb 25, 2021
Updated
Aug 3, 2024
Vendor
Microsoft
Product
Microsoft SharePoint Foundation 2013
Classifications
CWE-502, CAPEC-586, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 25, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.0.0 <publication

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Foundation 2013version=15.0.0 <publication
Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <publication
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <publication
Microsoft · Microsoft SharePoint Foundation 2010version=13.0.0 <publication

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
8.8Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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