Review reviewHigh

CVE-2021-34520

Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Foundation 2013 Service Pack 1, Microsoft SharePoint Server 2019

CVE-2021-34520 affects Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Foundation 2013 Service Pack 1, Microsoft SharePoint Server 2019. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

CVSS: 8.8
EPSS: 4.39%
CISA KEV: Not listed
Published: 2021.07.15

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability4.39%

Technical severityCVSS 8.8

Vulnerability overview

Affected product and versions

Product: Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Foundation 2013 Service Pack 1, Microsoft SharePoint Server 2019
Affected versions: >= 16.0.0 < 16.0.5188.1000, >= 15.0.0 < 15.0.5363.1000, >= 16.0.0 < 16.0.10376.20001, 2013, 2016, 2019
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Microsoft Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Foundation 2013 Service Pack 1, Microsoft SharePoint Server 2019 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-502