CVE-2023-21734: Microsoft Office Remote Code Execution Vulnerability

Overview

Severity

High (CVSS 7.8)

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Remote Code Execution

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2023-Jan

Released

2023-01-10

Last Updated

2023-01-10

EPSS Score

3.54% (percentile: 87.7%)

FAQ

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do? A user needs to be tricked into running malicious files. According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution? The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. The vulnerable endpoint is only available over the local VM interface as all external communication is blocked. This means an attacker needs to execute code from the local machine to exploit the vulnerability.

Affected Products (4)

Microsoft Office

• Microsoft Office 2019 for Mac
• Microsoft 365 Apps for Enterprise for 32-bit Systems
• Microsoft 365 Apps for Enterprise for 64-bit Systems
• Microsoft Office LTSC for Mac 2021

Security Updates (1)

• Release Notes

Acknowledgments

khangkito - Tran Van Khang (VinCSS) working with Trend Micro Zero Day Initiative

Revision History

• 2023-01-10: Information published.
• 2023-01-10: Microsoft is announcing the availability of the security updates for Microsoft Office for Mac. Customers running affected Mac software should install the update for their product to be protected from this vulnerability. Customers running other Microsoft Office software do not need to take any action. See the Release Notes for more information and download links.