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CVE-2018-6556· NVD / CVE Program· CNA canonical

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

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.

LowCVSS 3.3 · v3.0—No exploit Fix available
Published
Aug 10, 2018
Updated
Jun 16, 2026
EPSS
0.3% · 24th percentile
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Report tools

JSON

Action score

13

Monitor

Low priority for now.

CVSS
13 / 40 · 3.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

Affected systems

VendorProduct
canonicalubuntu linux
linuxcontainerslxc
susecaas platform
suseopenstack cloud
susesuse linux enterprise server
opensuseleap

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux18.04
  • linuxcontainers lxc2.0.0 and later · up to 2.0.9 inclusive
  • linuxcontainers lxc3.0.0 and later · before 3.0.2
  • opensuse leap15.0
  • suse caas platform1.0
  • suse caas platform2.0
  • suse openstack cloud6
  • suse suse linux enterprise server11

Versions reported by the vendor

Affected version ranges reported by the assigning authority (canonical). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a LXC

    • 2.0.9 and later · before 2.0*affected
    • 3.0.0 and later · before 3.0*affectedfixed in 3.0.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.10lxcfrom 2.0.0 · before 2.1.1-r92.1.1-r9
Alpine:v3.6lxcfrom 2.0.0 · before 2.0.9-r12.0.9-r1
Alpine:v3.7lxcfrom 2.0.0 · before 2.1.1-r32.1.1-r3
Debian:12lxcbefore 1:2.0.9-6.11:2.0.9-6.1
openSUSE:Leap 15.0lxcbefore 3.1.0-lp150.2.10.13.1.0-lp150.2.10.1
openSUSE:Leap 15.0lxcfsbefore 3.0.3-lp150.2.3.13.0.3-lp150.2.3.1
openSUSE:Tumbleweedlxcbefore 4.0.9-1.14.0.9-1.1
SUSE:Package Hub 15lxcbefore 2.0.9-bp150.5.6.12.0.9-bp150.5.6.1
SUSE:Package Hub 15lxcbefore 3.1.0-bp150.5.3.13.1.0-bp150.5.3.1
SUSE:Package Hub 15lxcfsbefore 3.0.3-bp150.3.3.13.0.3-bp150.3.3.1

Other highest-scoring records for the same primary product.

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    76This week
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    67This week
  • CVE-2017-14493Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code vi
    64This week
  • CVE-2016-4553client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when absolute-URI is provided, which al
    58Plan
  • CVE-2017-14495Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a
    55Plan
  • CVE-2016-4054Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Incl
    55Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
n/a LXC3.0.2Vendor (CNA)
alpine:lxc2.1.1-r9 · Alpine:v3.10Package registry (OSV)
debian:lxc1:2.0.9-6.1 · Debian:12Package registry (OSV)
opensuse:lxc3.1.0-lp150.2.10.1 · openSUSE:Leap 15.0Package registry (OSV)
opensuse:lxcfs3.0.3-lp150.2.3.1 · openSUSE:Leap 15.0Package registry (OSV)
suse:lxc3.1.0-bp150.5.3.1 · SUSE:Package Hub 15Package registry (OSV)
suse:lxcfs3.0.3-bp150.3.3.1 · SUSE:Package Hub 15Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

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