# CVE-2018-6954: libnss-myhostname: systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path components, which allows loc...

CVE-2018-6954 is fixed in 14 products on 1 platform, first by libnss-myhostname 237-3ubuntu10.9, released February 12, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-6954
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0053
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 12, 2018

## Description

systemd-tmpfiles in systemd through 237 mishandles symlinks present in non-terminal path components, which allows local users to obtain ownership of arbitrary files via vectors involving creation of a directory and a file under that directory, and later replacing that directory with a symlink. This occurs even if the fs.protected_symlinks sysctl is turned on.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libnss-myhostname Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libnss-myhostname 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-myhostname-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libnss-mymachines Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libnss-mymachines 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-mymachines-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libnss-resolve Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libnss-resolve 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-resolve-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libnss-systemd Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libnss-systemd 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-systemd-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libpam-systemd Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libpam-systemd 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpam-systemd-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libsystemd0 Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libsystemd0 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libsystemd0-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | libudev1 Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [libudev1 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libudev1-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd-container Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd-container 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-container-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd-coredump Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd-coredump 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-coredump-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd-journal-remote Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd-journal-remote 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-journal-remote-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd-sysv Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd-sysv 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-sysv-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | systemd-tests Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [systemd-tests 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-systemd-tests-237-3ubuntu10.9.md) | Feb 12, 2018 |
| Linux | udev Ubuntu 18.04.6 LTS (bionic) | 237-3ubuntu10.9 | [udev 237-3ubuntu10.9](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-udev-237-3ubuntu10.9.md) | Feb 12, 2018 |

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