How severe is CVE-2021-29627?

CVE-2021-29627 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-29627 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29627?

CVE-2021-29627 primarily affects Freebsd. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-29627?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-29627 published?

CVE-2021-29627 was published on 2021-04-07 and last updated on 2026-06-17.

CVE-2021-29627

CVE-2021-29627 is a high-severity vulnerability in Freebsd with a CVSS 3.x base score of 7.8. 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-415.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Freebsd
Published: 2021-04-07
Last modified: 2026-06-17

Description

In FreeBSD 13.0-STABLE before n245050, 12.2-STABLE before r369525, 13.0-RC4 before p0, and 12.2-RELEASE before p6, listening socket accept filters implementing the accf_create callback incorrectly freed a process supplied argument string. Additional operations on the socket can lead to a double free or use after free.

Frequently asked questions

What is CVE-2021-29627?: In FreeBSD 13.0-STABLE before n245050, 12.2-STABLE before r369525, 13.0-RC4 before p0, and 12.2-RELEASE before p6, listening socket accept filters implementing the accf_create callback incorrectly freed a process supplied argument string. Additional operations on the socket can lead to a double free or use after free.
How severe is CVE-2021-29627?: CVE-2021-29627 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-29627 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29627?: CVE-2021-29627 primarily affects Freebsd. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-29627?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-29627 published?: CVE-2021-29627 was published on 2021-04-07 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*
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:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:beta1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:beta2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:beta3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:beta4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:rc1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:rc2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:13.0:rc3:*:*:*:*:*:*

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