CVE-2018-6954

Name: CVE-2018-6954
Creator: NVD / NIST
Published: 2018-02-13T20:29:00.547+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2018-6954 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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.. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.53%

40.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Systemd Project	Systemd	<= 237
Canonical	Ubuntu Linux	16.04
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10
Opensuse	Leap	42.3

References

http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.htmlThird Party Advisory
https://github.com/systemd/systemd/issues/7986Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://usn.ubuntu.com/3816-1/Third Party Advisory
https://usn.ubuntu.com/3816-2/Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.htmlThird Party Advisory
https://github.com/systemd/systemd/issues/7986Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
https://usn.ubuntu.com/3816-1/Third Party Advisory
https://usn.ubuntu.com/3816-2/Third Party Advisory

Timeline

Published: Feb 13, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-6954?

How severe is CVE-2018-6954?

CVE-2018-6954 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2018-6954?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-6954?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST