Remote code execution in Microsoft Excel
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2021-43256 |
| CWE-ID | CWE-94 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
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
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-2021-43256
CWE-ID:
CWE-94 - Improper Control of Generation of Code ('Code Injection')
Exploit availability: No
DescriptionThe 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.
MitigationInstall updates from vendor's website.
Vulnerable software versionsOffice Online Server : 2016
Microsoft Office: 2019
Microsoft Excel: 2013 - 2016
Microsoft Office Web Apps Server: 2013 Service Pack 1
External linkshttp://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43256
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.
