All versions of Samba prior to 4.13.16 are vulnerable to a malicious client using an SMB1…
Priority LOW 13CWE-362Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Partial Red Hat: 3 fixed, 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
All versions of Samba prior to 4.13.16 are vulnerable to a malicious client using an SMB1 or NFS race to allow a directory to be created in an area of the server file system not exported under the share definition. Note that SMB1 has to be enabled, or the share also available via NFS in order for this attack to succeed.
Why it matters now
EPSS 0.00405 34th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 3 fixed, 3 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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Storage 3 | Affected | No fix yet |
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | — |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | — |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | — |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-43566
- 2026-10-03 Alias added: GHSA-rcx2-p86p-53w9
References
More Samba vulnerabilities
- TI-2020-01431 Netlogon Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2017-05139 Code injection in samba KEVCVSS 3.1CRITICAL 9.8
- TI-2015-00210 The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x… CVSS 2.0HIGH 10.0
- TI-2003-00081 Buffer overflow in the SMB/CIFS packet fragment re-assembly code for SMB daemon (smbd) in… CVSS 2.0HIGH 10.0
- TI-2003-00185 Buffer overflow in the call_trans2open function in trans2.c for Samba 2.2.x before… CVSS 2.0HIGH 10.0
- TI-2007-02362 Multiple heap-based buffer overflows in the NDR parsing in smbd in Samba 3.0.0 through… CVSS 2.0HIGH 10.0
Sources
- CVE-2021-43566 · CVE Program
- CVE-2021-43566 · NVD
- FIRST EPSS
- GHSA-rcx2-p86p-53w9 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-43566 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences