CVE-2021-27053: Microsoft Excel XLS File Parsing Use-After-Free Remote Code Execution Vulnerability

Published Mar 9, 2021
·
Updated

Microsoft Excel Remote Code Execution Vulnerability

Other sources

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Excel. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of XLS files. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process.

ZDI

Affected Software

22 affected componentsFixes available
Microsoft Office Online Server
Microsoft Excel 2013
Microsoft Excel 2013
Microsoft Excel 2010
Microsoft Excel 2010
Microsoft Excel 2013 RT
Microsoft Office Web Apps Server 2013
Microsoft Office 2019 for 32-bit editions
Microsoft Excel
Microsoft Office 2019 for 64-bit editions
Microsoft 365 Apps for Enterprise
Microsoft 365 Apps for Enterprise
Microsoft 365 Apps
Microsoft Excel=2010-sp2
Microsoft Excel=2013-sp1
Microsoft Excel=2013-sp1
Microsoft Excel=2016
Microsoft Office=2019
Microsoft Office Online Server
Microsoft Office Web Apps=2013-sp1
Microsoft Excel 2016
Microsoft Excel 2016

Event History

Mar 9, 2021
CVE Published
via Microsoft·08:00 AM
Data Sourced
via Microsoft·08:00 AM
DescriptionSeverityWeakness
Mar 11, 2021
CVE Published
via MITRE·03:46 PM
Data Sourced
via MITRE·03:46 PM
DescriptionSeverity
Feb 23, 2025
Advisory Published
via ZDI·10:12 AM
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2021-27053?

CVE-2021-27053 is a vulnerability that allows remote attackers to execute arbitrary code on affected installations of Microsoft Excel.

2

How severe is CVE-2021-27053?

CVE-2021-27053 has a severity rating of 7.8, which is considered high.

3

Which versions of Microsoft Excel are affected by CVE-2021-27053?

Microsoft Excel 2013, Excel 2016, Excel 2013 RT, and Excel 2010 are affected by CVE-2021-27053.

4

How can I fix CVE-2021-27053?

To fix CVE-2021-27053, you should install the appropriate patches provided by Microsoft for your version of Microsoft Excel.

5

Where can I find more information about CVE-2021-27053?

You can find more information about CVE-2021-27053 on the Microsoft Security Guidance Advisory page and the Zero Day Initiative advisories.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203