Race condition in kernel
Key facts
- Attack vector
- Local
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
A race condition was found in the Linux kernels implementation of the floppy disk drive controller driver software. The impact of this issue is lessened by the fact that the default permissions on the floppy device (/dev/fd0) are restricted to root. If the permissions on the device have changed the impact changes greatly. In the default configuration root (or equivalent) permissions are required to attack this flaw.
Why it matters now
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 |
|---|---|---|---|---|---|
| — | kernel | kernel 5.12-rc2 | — | No fix listed | CNA |
- kernel Vendor— Affected kernel 5.12-rc2 Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.5:-:*:*:*:*:*:* | 4.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.5:rc1:*:*:*:*:*:* | 4.5 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.5:rc2:*:*:*:*:*:* | 4.5 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.5:rc3:*:*:*:*:*:* | 4.5 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.5:rc4:*:*:*:*:*:* | 4.5 rc4 | Vulnerable | Linux |
| cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.5:-:*:*:*:*:*:* Versions 4.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.5:rc1:*:*:*:*:*:* Versions 4.5 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.5:rc2:*:*:*:*:*:* Versions 4.5 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.5:rc3:*:*:*:*:*:* Versions 4.5 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.5:rc4:*:*:*:*:*:* Versions 4.5 rc4 Vulnerable ·Linux
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20261
- 2026-10-03 Alias added: GHSA-8p2q-8rc4-vfp4
References
Sources
- CVE-2021-20261 · CVE Program
- CVE-2021-20261 · NVD
- FIRST EPSS
- GHSA-8p2q-8rc4-vfp4 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-20261 · Red Hat security data · CC BY 4.0
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