CVE-2017-18078

Name: CVE-2017-18078
Creator: NVD / NIST
Published: 2018-01-29T05:29:00.213+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 1.08%

Last modified Jun 17, 2026

CVE-2017-18078 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlinks sysctl is turned off, which allows local users to bypass intended access restrictions via vectors involving a hard link to a file for which the user lacks write access, as demonstrated by changing the ownership of the /etc/passwd file.. EPSS estimates a 1.08% chance of exploitation in the next 30 days.

Description

systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlinks sysctl is turned off, which allows local users to bypass intended access restrictions via vectors involving a hard link to a file for which the user lacks write access, as demonstrated by changing the ownership of the /etc/passwd file.

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

1.08%

61.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-59

Affected Software

Vendor	Product	Versions
Systemd Project	Systemd	< 237
Debian	Debian Linux	8.0
Opensuse	Leap	42.3

References

http://lists.opensuse.org/opensuse-updates/2018-02/msg00109.htmlMailing List, Third Party Advisory
http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
http://www.openwall.com/lists/oss-security/2018/01/29/3Exploit, Mailing List, Third Party Advisory
https://github.com/systemd/systemd/issues/7736Exploit, Issue Tracking, 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://lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlMailing List, Third Party Advisory
https://www.exploit-db.com/exploits/43935/Exploit, Third Party Advisory, VDB Entry
https://www.openwall.com/lists/oss-security/2018/01/29/4Mailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-updates/2018-02/msg00109.htmlMailing List, Third Party Advisory
http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
http://www.openwall.com/lists/oss-security/2018/01/29/3Exploit, Mailing List, Third Party Advisory
https://github.com/systemd/systemd/issues/7736Exploit, Issue Tracking, 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://lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlMailing List, Third Party Advisory
https://www.exploit-db.com/exploits/43935/Exploit, Third Party Advisory, VDB Entry
https://www.openwall.com/lists/oss-security/2018/01/29/4Mailing List, Third Party Advisory

Timeline

Published: Jan 29, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-18078?

How severe is CVE-2017-18078?

CVE-2017-18078 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 1.08% probability of exploitation in the next 30 days.

How do I fix CVE-2017-18078?

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-2017-18078?

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

Scan your code now

Source: NVD / NIST