What is CVE-2021-43772?

CVE-2021-43772 is a medium-severity vulnerability in Microsoft Windows, classified under Files or Directories Accessible to External Parties. CVSS score: 5.5/10. Published 2021-12-03.

How severe is CVE-2021-43772?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Microsoft Windows

CVE-2021-43772

Trend Micro Security 2021 v17.0 (Consumer) contains a vulnerability that allows files inside the protected folder to be modified without any detection.

Published 2021-12-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.2th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-552 — Files or Directories Accessible to External Parties

References

helpcenter.trendmicro.com/en-us/article/tmka-10855 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-43772?: CVE-2021-43772 is a medium-severity vulnerability in Microsoft Windows, classified under Files or Directories Accessible to External Parties. CVSS score: 5.5/10. Published 2021-12-03.
How severe is CVE-2021-43772?: Medium severity. CVSS v3 base score is 5.5 out of 10.