cve/2017/CVE-2017-18078.md

CVE-2017-18078

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.

POC

Reference

• http://packetstormsecurity.com/files/146184/systemd-Local-Privilege-Escalation.html
• http://www.openwall.com/lists/oss-security/2018/01/29/3
• https://www.exploit-db.com/exploits/43935/

Github

• https://github.com/blackberry/UBCIS
• https://github.com/flyrev/security-scan-ci-presentation