How severe is CVE-2020-25578?

CVE-2020-25578 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2020-25578 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-25578?

CVE-2020-25578 primarily affects Freebsd. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-25578?

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

When was CVE-2020-25578 published?

CVE-2020-25578 was published on 2021-03-26 and last updated on 2026-06-17.

CVE-2020-25578

CVE-2020-25578 is a medium-severity vulnerability in Freebsd with a CVSS 3.x base score of 5.3. 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-665.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-665
Affected product: Freebsd
Published: 2021-03-26
Last modified: 2026-06-17

Description

In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 several file systems were not properly initializing the d_off field of the dirent structures returned by VOP_READDIR. In particular, tmpfs(5), smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, eight uninitialized kernel stack bytes may be leaked to userspace by these file systems.

Frequently asked questions

What is CVE-2020-25578?: In FreeBSD 12.2-STABLE before r368969, 11.4-STABLE before r369047, 12.2-RELEASE before p3, 12.1-RELEASE before p13 and 11.4-RELEASE before p7 several file systems were not properly initializing the d_off field of the dirent structures returned by VOP_READDIR. In particular, tmpfs(5), smbfs(5), autofs(5) and mqueuefs(5) were failing to do so. As a result, eight uninitialized kernel stack bytes may be leaked to userspace by these file systems.
How severe is CVE-2020-25578?: CVE-2020-25578 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2020-25578 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-25578?: CVE-2020-25578 primarily affects Freebsd. In total, 23 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-25578?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-25578 published?: CVE-2020-25578 was published on 2021-03-26 and last updated on 2026-06-17.

References

Affected products (23)

cpe:2.3:o:freebsd:freebsd:11.4:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:11.4:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p10:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p11:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p12:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p7:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p8:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.1:p9:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.2:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.2:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.2:p2:*:*:*:*:*:*

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