CVE-2018-6954 — systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-termi
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 w
Published
2018-02-13T20:00:00.000Z
Last modified
2025-06-09T15:54:51.003Z
01What is this vulnerability?
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.
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2018-02-13T20:00:00.000Z
- Last modified: 2025-06-09T15:54:51.003Z
09References
- usn.ubuntu.com — https://usn.ubuntu.com/3816-2/
- github.com — https://github.com/systemd/systemd/issues/7986
- usn.ubuntu.com — https://usn.ubuntu.com/3816-1/
- lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html
- lists.apache.org — https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8…
- lists.apache.org — https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e3…
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