Skip to content
Fencer Vulns
low 3.3

CVE-2018-6556 json

The lxc-user-nic component of LXC allows unprivileged users to open arbitrary files

published 2018-08-10 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18308

cvss
3.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

lxc-user-nic when asked to delete a network interface will unconditionally open a user provided path. This code path may be used by an unprivileged user to check for the existence of a path which they wouldn't otherwise be able to reach. It may also be used to trigger side effects by causing a (read-only) open of special kernel files (ptmx, proc, sys). Affected releases are LXC: 2.0 versions above and including 2.0.9; 3.0 versions above and including 3.0.0, prior to 3.0.2.

Patch / fix

  • n/a LXC 3.0.2
  • lxc Debian 14, Debian 13, Debian 12 1:2.0.9-6.1

debian advisories DEBIAN-CVE-2018-6556

  • lxc Ubuntu 18.04 LTS 3.0.1-0ubuntu1~18.04.2

ubuntu advisories UBUNTU-CVE-2018-6556

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lxc openSUSE Tumbleweed 4.0.9-1.1
  • lxcfs openSUSE Leap 15.0 3.0.3-lp150.2.3.1
  • lxc openSUSE Leap 15.0 3.1.0-lp150.2.10.1
  • lxc Package Hub 15 2.0.9-bp150.5.6.1
  • lxcfs Package Hub 15 3.0.3-bp150.3.3.1
  • lxc Package Hub 15 3.1.0-bp150.5.3.1

opensuse advisories openSUSE-SU-2024:11030-1openSUSE-SU-2019:1275-1openSUSE-SU-2019:1230-1openSUSE-SU-2019:1227-1

  • lxc Alpine 3.24, Alpine 3.23, Alpine 3.22 +14 more 2.1.1-r9
  • lxc Alpine 3.6 2.0.9-r1
  • lxc Alpine 3.7 2.1.1-r3

alpine advisories ALPINE-CVE-2018-6556

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lxc Arch Linux 1:3.0.2-1

arch linux advisories AVG-754

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-6556 updated cvss 5.5

lxc: lxc-user-nic allows for open() of arbitrary paths

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 3.3 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a LXC

Classification

Weakness
  • CWE-417 Communication Channel Errors

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.