CVE-2017-18078

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 v3.1

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

CVSS v2.0

4.6 MEDIUMAV:L/AC:L/Au:N/C:P/I:P/A:P

EPSS

1.06% chance of exploitation in the next 30 days, 62th percentile

Published

2018-01-29

Updated

2024-08-05

Proof-of-concept exploits (2)

• http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.html
• http://www.openwall.com/lists/oss-security/2018/01/29/3

ExploitDB entries (1)

• https://www.exploit-db.com/exploits/43935

References

• CVE Record
• NVD entry

Related

• CVE-2017-18077
• CVE-2017-18123
• CVE-2017-18049
• CVE-2017-18175
• CVE-2017-18048
• CVE-2017-18176