Incorrect default permissions in grub2
Priority LOW 16CWE-276Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 1 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
EPSS 0.00319 25th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | grub2 | grub2 2.06 and previous versions | — | No fix listed | CNA |
- grub2 Vendor— Affected grub2 2.06 and previous versions Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* | up to 2.06 | Vulnerable | GNU |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
- cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* Versions up to 2.06 Vulnerable ·GNU
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
Remediation
Red Hat 1 advisory
- RHSA-2022:2110 Released 2022-05-10 · Red Hat rating Lowgrub2 security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) grub2-1:2.02-123.el8, grub2-common-1:2.02-123.el8, grub2-efi-aa64-1:2.02-123.el8 +16
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2022:2110 |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3981
- 2026-10-03 Alias added: GHSA-6hfm-rxpf-979r
References
Sources
- CVE-2021-3981 · CVE Program
- CVE-2021-3981 · NVD
- FIRST EPSS
- GHSA-6hfm-rxpf-979r · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3981 · Red Hat security data · CC BY 4.0
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