Vulnerability identifier: #VU56573

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-38655

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Microsoft Office
Client/Desktop applications / Office applications
Microsoft Excel
Client/Desktop applications / Office applications
Office Online Server
Server applications / Other server solutions
Microsoft Office Web Apps Server
Server applications / Application servers

Vendor: Microsoft

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft Office: 2019 - 2019 for Mac

Office Online Server : 2016

Microsoft Excel:

Microsoft Office Web Apps Server: 2013 Service Pack 1

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External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38655

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.