Public exploit available
Public proof-of-concept or exploit code exists (ExploitDB / Metasploit / Nuclei).

CVE-2017-18078

CWE-59CWE-3679 documents8 sources
Severity
7.8HIGH
EPSS
0.1%
top 75.50%
CISA KEV
Not in KEV
Exploit
PoC available
Public exploit / PoC exists
Timeline
PublishedJan 29
Latest updateMay 13

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.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages3 packages

Debiansystemd< 237-1+3
NVDopensuse/leap42.3

Also affects: Debian Linux 8.0

🔴Vulnerability Details

3
GHSA
GHSA-g2wx-phqf-j84q: systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs2022-05-13
CVEList
CVE-2017-18078: systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs2018-01-29
OSV
CVE-2017-18078: systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs2018-01-29

💥Exploits & PoCs

1
Exploit-DB
systemd (systemd-tmpfiles) < 236 - 'fs.protected_hardlinks=0' Local Privilege Escalation2018-01-29

📋Vendor Advisories

2
Red Hat
systemd: Unsafe handling of hard links allowing privilege escalation2017-12-24
Debian
CVE-2017-18078: systemd - systemd-tmpfiles in systemd before 237 attempts to support ownership/permission ...2017

💬Community

2
Bugzilla
CVE-2017-18078 systemd: Unsafe handling of hard links allowing privilege escalation [fedora-all]2018-01-30
Bugzilla
CVE-2017-18078 systemd: Unsafe handling of hard links allowing privilege escalation2018-01-29
CVE-2017-18078 (HIGH CVSS 7.8) | systemd-tmpfiles in systemd before | cvebase.io