ReviewHigh

CVE-2021-34518

Microsoft Microsoft Excel 2013 Service Pack 1, Microsoft Excel 2016, Microsoft Office Web Apps Server 2013 Service Pack 1

CVE-2021-34518 affects Microsoft Microsoft Excel 2013 Service Pack 1, Microsoft Excel 2016, Microsoft Office Web Apps Server 2013 Service Pack 1. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

CVSS: 7.8
EPSS: 2.33%
CISA KEV: Not listed
Published: 2021.07.15

PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability2.33%

Technical severityCVSS 7.8

Vulnerability overview

Affected product and versions

Product: Microsoft Microsoft Excel 2013 Service Pack 1, Microsoft Excel 2016, Microsoft Office Web Apps Server 2013 Service Pack 1
Affected versions: >= 15.0.0.0 < 15.0.5363.1000, >= 16.0.0.0 < 16.0.5188.100, >= 15.0.1 < 15.0.5363.1000, 2013, 2016
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 Excel 2013 Service Pack 1, Microsoft Excel 2016, Microsoft Office Web Apps Server 2013 Service Pack 1 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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE: Not available