Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.35% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2018
CVE-2018-6556High confidence
The lxc-user-nic component of LXC allows unprivileged users to open arbitrary files
Unknown · LXC
3.3LowCVSS 3.0
Scheduled
Patch availableLow technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityLow→Operational priority:Low, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown LXC and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Distribution package intelligence
7 package statesRelease-specific package status
Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Alpine v3.23v3.23 · main | lxc | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.1.1-r9 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.22v3.22 · main | lxc | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.1.1-r9 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.21v3.21 · main | lxc | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 2.1.1-r9 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Debian trixietrixie · source | lxc | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.0.9-6.1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | lxc | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.0.9-6.1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | lxc | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.0.9-6.1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | lxc | Vendor fix publishedDebian records a fixed source-package version for this release. | 1:2.0.9-6.1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
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.
What
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.
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
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.
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-417 ↗
CWE-417. Open the MITRE definition for the exact weakness description.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NCommon Vulnerability Scoring System 3.0: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- LXC: 2.0.9 < 2.0*, 3.0.0 < 3.0*
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 10 Aug 2018 · Last source change 17 Sept 2024, 03:38 UTC · CWE-417
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-09-01
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2018-18308
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2018-18308 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2018-18308"}
- Vendor guidanceAuthoritative vendor guidance changed: added patch: bugzilla.suse.com/show_bug.cgi?id=988348; added remediation: bugzilla.suse.com/show_bug.cgi?id=988348; removed vendor advisory: lists.opensuse.org/msg00073.html; removed vendor advisory: lists.opensuse.org/msg00074.html; 4 further removals.bugzilla.suse.com ↗
- Before
- vendor advisory: lists.opensuse.org/msg00073.html · vendor advisory: lists.opensuse.org/msg00074.html · vendor advisory: lists.opensuse.org/msg00076.html · 3 more references
- After
- patch: bugzilla.suse.com/show_bug.cgi?id=988348 · remediation: bugzilla.suse.com/show_bug.cgi?id=988348
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- 2.0.9 < 2.0*; 3.0.0 < 3.0* · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- 2.0.9 < 2.0*; 3.0.0 < 3.0* · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.bugzilla.suse.com ↗
- Before
- Awaiting fix
- After
- Patch available
- SeveritySeverity changed from Unknown to Low.NIST NVD ↗
- Before
- Unknown
- After
- Low
- CVSS scoreCVSS score changed from not recorded to 3.3 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).NIST NVD ↗
- Before
- not recorded
- After
- 3.3 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N)
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.