How severe is CVE-2021-43413?

CVE-2021-43413 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43413 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43413?

CVE-2021-43413 affects Gnu Hurd. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43413?

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-2021-43413 published?

CVE-2021-43413 was published on 2021-11-07 and last updated on 2026-06-17.

CVE-2021-43413

CVE-2021-43413 is a high-severity vulnerability in Gnu Hurd with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Gnu Hurd
Published: 2021-11-07
Last modified: 2026-06-17

Description

An issue was discovered in GNU Hurd before 0.9 20210404-9. A single pager port is shared among everyone who mmaps a file, allowing anyone to modify any files that they can read. This can be trivially exploited to get full root access.

Frequently asked questions

What is CVE-2021-43413?: An issue was discovered in GNU Hurd before 0.9 20210404-9. A single pager port is shared among everyone who mmaps a file, allowing anyone to modify any files that they can read. This can be trivially exploited to get full root access.
How severe is CVE-2021-43413?: CVE-2021-43413 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43413 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43413?: CVE-2021-43413 affects Gnu Hurd. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43413?: 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-2021-43413 published?: CVE-2021-43413 was published on 2021-11-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gnu:hurd:*:*:*:*:*:*:*:*

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