Vulnerability 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 Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Systemd Project | Systemd | < 237 |
| Debian | Debian Linux | 8.0 |
| Opensuse | Leap | 42.3 |
Related Weaknesses (CWE)
References
- http://lists.opensuse.org/opensuse-updates/2018-02/msg00109.htmlMailing ListThird Party Advisory
- http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.hExploitThird Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2018/01/29/3ExploitMailing ListThird Party Advisory
- https://github.com/systemd/systemd/issues/7736ExploitIssue TrackingThird Party Advisory
- https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e3
- https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8
- https://lists.debian.org/debian-lts-announce/2019/04/msg00022.htmlMailing ListThird Party Advisory
- https://www.exploit-db.com/exploits/43935/ExploitThird Party AdvisoryVDB Entry
- https://www.openwall.com/lists/oss-security/2018/01/29/4Mailing ListThird Party Advisory
- http://lists.opensuse.org/opensuse-updates/2018-02/msg00109.htmlMailing ListThird Party Advisory
- http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.hExploitThird Party AdvisoryVDB Entry
- http://www.openwall.com/lists/oss-security/2018/01/29/3ExploitMailing ListThird Party Advisory
- https://github.com/systemd/systemd/issues/7736ExploitIssue TrackingThird Party Advisory
- https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e3
- https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8
FAQ
What is CVE-2017-18078?
CVE-2017-18078 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 ...
How severe is CVE-2017-18078?
CVE-2017-18078 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2017-18078?
Check the references section above for vendor advisories and patch information. Affected products include: Systemd Project Systemd, Debian Debian Linux, Opensuse Leap.