CVE-2017-18078

high

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.

References

https://github.com/systemd/systemd/issues/7736

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

https://www.openwall.com/lists/oss-security/2018/01/29/4

http://www.openwall.com/lists/oss-security/2018/01/29/3

http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.html

http://lists.opensuse.org/opensuse-updates/2018-02/msg00109.html

https://lists.debian.org/debian-lts-announce/2019/04/msg00022.html

https://lists.apache.org/thread.html/[email protected]%3Cissues.bookkeeper.apache.org%3E

https://lists.apache.org/thread.html/[email protected]%3Cissues.bookkeeper.apache.org%3E

Details

Source: MITRE

Published: 2018-01-29

Updated: 2021-06-29

Type: CWE-59

Risk Information

CVSS v2

Base Score: 4.6

Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Impact Score: 6.4

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3

Base Score: 7.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 1.8

Severity: HIGH