systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path…
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path components, which allows local users to obtain ownership of arbitrary files via vectors involving creation of a directory and a file under that directory, and later replacing that directory with a symlink. This occurs even if the fs.protected_symlinks sysctl is turned on.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
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
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* | up to 237 | Vulnerable | systemd |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* | 18.10 | Vulnerable | Canonical |
| cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:* | 42.3 | Vulnerable | openSUSE |
- cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:* Versions up to 237 Vulnerable ·systemd
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* Versions 18.10 Vulnerable ·Canonical
- cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:* Versions 42.3 Vulnerable ·openSUSE
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 7 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2018-6954
- 2026-10-03 Alias added: GHSA-fgm4-rh7c-g9fg
References
Other 2
- [bookkeeper-issues] 20210628 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
- [bookkeeper-issues] 20210629 [GitHub] [bookkeeper] padma81 opened a new issue #2746: Security Vulnerabilities in CentOS 7 image, Upgrade image to CentOS 8
Sources
- CVE-2018-6954 · CVE Program
- CVE-2018-6954 · NVD
- FIRST EPSS
- GHSA-fgm4-rh7c-g9fg · GitHub Advisory Database · CC BY 4.0
- CVE-2018-6954 · 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