How severe is CVE-2021-3981?

CVE-2021-3981 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-3981 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3981?

CVE-2021-3981 primarily affects Gnu Grub2. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3981?

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

When was CVE-2021-3981 published?

CVE-2021-3981 was published on 2022-03-10 and last updated on 2026-06-17.

CVE-2021-3981

CVE-2021-3981 is a low-severity vulnerability in Gnu Grub2 with a CVSS 3.x base score of 3.3. 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-276.

Key facts

Severity: Low (CVSS 3.x base score 3.3)
CVSS v2: 2.1
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-276
Affected product: Gnu Grub2
Published: 2022-03-10
Last modified: 2026-06-17

Description

A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.

Frequently asked questions

What is CVE-2021-3981?: A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong permission set allowing non privileged users to read its content. This represents a low severity confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg. This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no version with the fix is currently released.
How severe is CVE-2021-3981?: CVE-2021-3981 has a CVSS 3.x base score of 3.3, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-3981 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3981?: CVE-2021-3981 primarily affects Gnu Grub2. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3981?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3981 published?: CVE-2021-3981 was published on 2022-03-10 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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