CVE-2021-20675: M-System DL8 series (type A (DL8-A) versions prior to Ver3.0, type B (DL8-B) versions prior to Ver3.0, type C

Q: How do I fix CVE-2021-20675?

dl8-a firmware: upgrade to 3.0.81; dl8-b firmware: upgrade to 3.0.77; dl8-c firmware: upgrade to 3.0.99. Exact commands for each OS are on this page.

Q: Is CVE-2021-20675 being exploited?

CVE-2021-20675 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-20675 affect?

CVE-2021-20675 affects dl8-a firmware, dl8-b firmware, dl8-c firmware. Severity is medium (CVSS 6.5). 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 rem

Q: How urgent is CVE-2021-20675?

Priority 41/100. No elevated risk signals yet.

This month

MEDIUM 6.5UPGRADEUPGRADEUPGRADE

CVE-2021-20675 is a medium-severity flaw (CVSS 6.5) affecting dl8-a firmware, dl8-b firmware, dl8-c firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 cause a denial of service (DoS) condition via unspecified vectors.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Published	2021-03-18
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: m-system

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-03-18 01:15 UTCPublished CVE record published
2026-06-17 03:34 UTCUpdated Record last modified

m-system dl8-a firmware UPGRADE

Affected: < 3.0.81

Fixed in: 3.0.81

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

m-system dl8-b firmware UPGRADE

Affected: < 3.0.77

Fixed in: 3.0.77

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

m-system dl8-c firmware UPGRADE

Affected: < 3.0.99

Fixed in: 3.0.99

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

m-system dl8-d firmware UPGRADE

Affected: < 3.0.91

Fixed in: 3.0.91

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

m-system dl8-e firmware UPGRADE

Affected: < 3.0.12

Fixed in: 3.0.12

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-20675?

dl8-a firmware: upgrade to 3.0.81; dl8-b firmware: upgrade to 3.0.77; dl8-c firmware: upgrade to 3.0.99. Exact commands for each OS are on this page.

Is CVE-2021-20675 being exploited?

CVE-2021-20675 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-20675 affect?

CVE-2021-20675 affects dl8-a firmware, dl8-b firmware, dl8-c firmware. Severity is medium (CVSS 6.5). 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 rem

How urgent is CVE-2021-20675?

Priority 41/100. No elevated risk signals yet.

Related CVEs

CVE-2021-20676 MEDIUM 4.3 UPGRADE UPGRADE M-System DL8 series (type A (DL8-A) versions prior to Ver3.0, type B (DL8-B) versions prior to Ver3.0, type C

References

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