Remote code execution in Microsoft Excel

Published: 2021-12-14
Risk High
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-43256
Exploitation vector Network
Public exploit N/A
Vulnerable software
Office Online Server
Server applications / Other server solutions

Microsoft Office
Client/Desktop applications / Office applications

Microsoft Excel
Client/Desktop applications / Office applications

Microsoft Office Web Apps Server
Server applications / Application servers

Vendor Microsoft

Security Bulletin

This security bulletin contains one high risk vulnerability.

1) Code Injection

EUVDB-ID: #VU58907

Risk: High


CVE-ID: CVE-2021-43256

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in Microsoft Excel. A remote attacker can execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Install updates from vendor's website.

Vulnerable software versions

Office Online Server : 2016

Microsoft Office: 2019

Microsoft Excel: 2013 - 2016

Microsoft Office Web Apps Server: 2013 Service Pack 1

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?