What is CVE-2021-20676?

CVE-2021-20676 is a medium-severity vulnerability in M-System Dl8-A, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2021-03-18.

How severe is CVE-2021-20676?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in M-System Dl8-A

CVE-2021-20676

M-System DL8 series (type A (DL8-A) versions prior to Ver3.0, type B (DL8-B) versions prior to Ver3.0, type C (DL8-C) versions prior to Ver3.0, type D (DL8-D) versions prior to Ver3.0, and type E (DL8-E) versions prior to Ver3.0) allows remote authenticated attackers to bypass access restriction and conduct prohibited operations via unspecified vectors.

Vulnerability class: Broken Access Control

Published 2021-03-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (53.9th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

www.m-system.co.jp/download_w/dl_dl8updaterE.html (Vendor Advisory)
jvn.jp/en/jp/JVN47497535/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20676?: CVE-2021-20676 is a medium-severity vulnerability in M-System Dl8-A, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2021-03-18.
How severe is CVE-2021-20676?: Medium severity. CVSS v3 base score is 4.3 out of 10.