CVE-2017-18078

systemd: Unsafe handling of hard links allowing privilege escalation

Published Jan 29, 2018 CVSS 3.1 · 7.8 High EPSS 1.1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-1762-1 systemd security update
Debian DLA Debian DLA DLA-1762-2 systemd regression update
EUVD EUVD EUVD-2017-9215 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.
History
Type Values Removed Values Added
Metrics epss

{'score': 0.00202}

epss

{'score': 0.00106}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 5, 2024, 9:13 PM
Reserved
Jan 28, 2018, 12:00 AM
Status
Modified
Published
Jan 29, 2018, 5:29 AM
Modified
Jun 17, 2026, 1:12 AM
Severity
Moderate
Public date
Dec 24, 2017, 12:00 AM