CVE-2021-31939: Microsoft Excel XLS File Parsing Use-After-Free Remote Code Execution Vulnerability

Published Jun 8, 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.

Affected Software

27 affected componentsFixes available
Microsoft Office Online Server
Microsoft Excel 2013
Microsoft Excel 2013
Microsoft Office 2013
Microsoft Office 2013
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 Office 2016
Microsoft Office 2016
Microsoft 365 Apps for Enterprise
Microsoft 365 Apps for Enterprise
Microsoft 365 Apps
Microsoft Excel=2013-sp1
Microsoft Excel=2013-sp1
Microsoft Excel=2016
Microsoft Office=2013-sp1
Microsoft Office=2013-sp1
Microsoft Office=2016
Microsoft Office=2019
Microsoft Office Online Server
Microsoft Office Web Apps Server=2013-sp1
Microsoft Excel 2016
Microsoft Excel 2016
Microsoft Office 2013 RT

Event History

Jun 8, 2021
CVE Published
via Microsoft·07:00 AM
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeakness
CVE Published
via MITRE·10:46 PM
Data Sourced
via MITRE·10:46 PM
DescriptionSeverity
Feb 23, 2025
Advisory Published
via ZDI·10:12 AM
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Frequently Asked Questions

1

What is the severity of CVE-2021-31939?

The severity of CVE-2021-31939 is high with a CVSS score of 7.8.

2

How does CVE-2021-31939 affect Microsoft Excel?

CVE-2021-31939 allows remote attackers to execute arbitrary code on affected installations of Microsoft Excel.

3

What is the impact of CVE-2021-31939?

The impact of CVE-2021-31939 is remote code execution, which could lead to unauthorized access, data leakage, or system compromise.

4

Is user interaction required to exploit CVE-2021-31939?

Yes, user interaction is required to exploit CVE-2021-31939, such as visiting a malicious page or opening a malicious file.

5

How can I fix CVE-2021-31939?

To fix CVE-2021-31939, it is recommended to apply the latest security updates provided by Microsoft.

Contact

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