CVE-2021-43395: An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r

Q: How do I fix CVE-2021-43395?

illumos: upgrade to 2022-01-18; omnios: mitigate or apply the listed mitigation; openindiana: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2021-43395 being exploited?

CVE-2021-43395 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-2021-43395 affect?

CVE-2021-43395 affects illumos, omnios, openindiana. Severity is medium (CVSS 5.5). An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via cra

Q: How urgent is CVE-2021-43395?

Priority 31/100. Public exploit reference

Routine

MEDIUM 5.5UPGRADEMITIGATEMITIGATE

CVE-2021-43395 is a medium-severity flaw (CVSS 5.5) affecting illumos, omnios, openindiana. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via crafted rename and rmdir calls on tmpfs filesystems. Oracle Solaris 10 and 11 is also affected.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 75%)
CISA exploited list	No
Weakness	CWE-667
Published	2022-12-26
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: illumos · joyent · omniosce · openindiana · oracle

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

Am I affected?

Timeline

2022-12-26 06:15 UTCPublished CVE record published
2026-06-17 04:10 UTCUpdated Record last modified

illumos illumos UPGRADE

Affected: < 2022-01-18

Fixed in: 2022-01-18

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.

omniosce omnios MITIGATE

Affected: r151038

Fixed in: no fixed release known

Safe to downgrade to: a release before r151038

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.

openindiana openindiana MITIGATE

Affected: hipster_2021.04

Fixed in: no fixed release known

Safe to downgrade to: a release before hipster_2021.04

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.

joyent smartos MITIGATE

Affected: 20210923

Fixed in: no fixed release known

Safe to downgrade to: a release before 20210923

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.

oracle solaris MITIGATE

Affected: 10 · 11

Fixed in: no fixed release known

Safe to downgrade to: a release before 10

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-2021-43395?

illumos: upgrade to 2022-01-18; omnios: mitigate or apply the listed mitigation; openindiana: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-43395 being exploited?

CVE-2021-43395 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-2021-43395 affect?

CVE-2021-43395 affects illumos, omnios, openindiana. Severity is medium (CVSS 5.5). An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via cra

How urgent is CVE-2021-43395?

Priority 31/100. Public exploit reference

Related CVEs

CVE-2019-9579 HIGH 8.1 MITIGATE MITIGATE An issue was discovered in Illumos in Nexenta NexentaStor 4.0.5 and 5.1.2, and other products

References

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