How severe is CVE-2021-42315?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Microsoft Defender For Iot

CVE-2021-42315

Microsoft Defender for IoT Remote Code Execution Vulnerability

Published 2021-12-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.022 (81.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000

Affected products

Microsoft Defender For Iot
Microsoft Defender For Iot — versions 22.0.0

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42315 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-42315?: CVE-2021-42315 is a high-severity vulnerability in Microsoft Defender For Iot. CVSS score: 8.8/10. Published 2021-12-15.
How severe is CVE-2021-42315?: High severity. CVSS v3 base score is 8.8 out of 10.