How severe is CVE-2021-43566?

CVE-2021-43566 has a CVSS 3.x base score of 2.5, rated low severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-43566 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43566?

CVE-2021-43566 affects Samba. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43566?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-43566 published?

CVE-2021-43566 was published on 2022-01-11 and last updated on 2026-06-17.

CVE-2021-43566

CVE-2021-43566 is a low-severity vulnerability in Samba with a CVSS 3.x base score of 2.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

Severity: Low (CVSS 3.x base score 2.5)
CVSS v2: 1.2
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-362
Affected product: Samba
Published: 2022-01-11
Last modified: 2026-06-17

Description

All versions of Samba prior to 4.13.16 are vulnerable to a malicious client using an SMB1 or NFS race to allow a directory to be created in an area of the server file system not exported under the share definition. Note that SMB1 has to be enabled, or the share also available via NFS in order for this attack to succeed.

Frequently asked questions

What is CVE-2021-43566?: All versions of Samba prior to 4.13.16 are vulnerable to a malicious client using an SMB1 or NFS race to allow a directory to be created in an area of the server file system not exported under the share definition. Note that SMB1 has to be enabled, or the share also available via NFS in order for this attack to succeed.
How severe is CVE-2021-43566?: CVE-2021-43566 has a CVSS 3.x base score of 2.5, rated low severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-43566 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43566?: CVE-2021-43566 affects Samba. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43566?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43566 published?: CVE-2021-43566 was published on 2022-01-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*

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