From csirt.cy
Zero-day and publicly disclosed vulnerabilities fixed
Microsoft fixed both a zero-day and a publicly disclosed vulnerability as part of the January 2021 security updates.
Microsoft states that they have fixed a zero-day Microsoft Defender remote code execution vulnerability with a CVE of CVE-2021-1647.
This zero-day vulnerability is fixed in Microsoft Malware Protection Engine version 1.1.17700.4 or later, as shown below.