BlackTreeCVE Intelligence
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Full vulnerability report · 2018
CVE-2018-5407High confidence

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'

Unknown · Processors supporting Simultaneous Multi-Threading

Official source article: Red Hat RHSA-2019:0483 ↗. Check the applicable product and release in the original source.

4.7MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 3.42% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown Processors supporting Simultaneous Multi-Threading and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

4 package states
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 releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourceopensslVendor fix publishedDebian records a fixed source-package version for this release.1.1.1~~pre9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourceopensslVendor fix publishedDebian records a fixed source-package version for this release.1.1.1~~pre9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourceopensslVendor fix publishedDebian records a fixed source-package version for this release.1.1.1~~pre9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourceopensslVendor fix publishedDebian records a fixed source-package version for this release.1.1.1~~pre9-1Debian Security Tracker ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

0 current · 1 archived
CVE-2018-5407 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityopenssl: Side-channel vulnerability on SMT/Hyper-Threading architectures (PortSmash)No longer in the provider’s current catalogue
17 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • openssl.src as a component of Red Hat Enterprise Linux 5
  • openssl097a.src as a component of Red Hat Enterprise Linux 5
  • openssl as a component of Red Hat Enterprise Linux 6
  • openssl-devel as a component of Red Hat Enterprise Linux 6
  • openssl-perl as a component of Red Hat Enterprise Linux 6
  • openssl-static as a component of Red Hat Enterprise Linux 6
  • openssl.src as a component of Red Hat Enterprise Linux 6
  • openssl098e as a component of Red Hat Enterprise Linux 6
  • openssl098e.src as a component of Red Hat Enterprise Linux 6
  • openssl098e as a component of Red Hat Enterprise Linux 7
  • openssl098e.src as a component of Red Hat Enterprise Linux 7
  • compat-openssl10 as a component of Red Hat Enterprise Linux 8
Summary
A microprocessor side-channel vulnerability was found on SMT (e.g, Hyper-Threading) architectures. An attacker running a malicious process on the same core of the processor as the victim process can extract certain secret information.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted. After installing the updated packages, the httpd daemon will be restarted automatically.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2018-17177

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

What

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

Why

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

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

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

Why

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

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
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

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
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Exposure of Sensitive Information to an Unauthorized Actor → 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
High: exploitation depends on specific conditions
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-200 ↗

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.CHighConfidentiality impact: A successful attack can cause a major 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.
CWE-200Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2023-1594IBM Tivoli Network Manager: Mehrere Schwachstellen

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in IBM Tivoli Network Manager ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand herbeizuführen, seine Privilegien auszuweiten, Daten zu manipulieren, nicht spezifizierte Auswirkungen zu verursachen und einen Cross-Site-Scripting-Angriff durchzuführen.

Official advisory ↗
BSI · German · WID-SEC-2022-0517Red Hat Enterprise Linux: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um dadurch die Integrität, Vertraulichkeit und Verfügbarkeit zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2025-2349Intel Prozessoren: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein lokaler Angreifer kann eine Schwachstelle in Intel Prozessoren ausnutzen, um Informationen offenzulegen und Sicherheitsvorkehrungen zu umgehen.

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-267Multiples vulnérabilités dans Juniper Networks Junos Space

CVERecord?id=CVE-2018-20060 Référence CVE CVE-2018-20169 https://www.cve.org/CVERecord?id=CVE-2018-20169 Référence CVE CVE-2018-20836 https://www.cve.org/CVERecord?id=CVE-2018-20836 Référence CVE CVE-2018-20843 https://www.cve.org/CVERecord?id=CVE-2018-20843 Référence CVE CVE-2018-20852 https://www.cve.org/CVERecord?id=CVE-2018-20852 Référence CVE CVE-2018-3639 https://www.cve.org/CVERecord?id=CVE-2018-3639 Référence CVE CVE-2018-4180 https://www.cve.org/CVERecord?id=CVE-2018-4180 Référence CVE CVE-2018-4181 https://www.cve.org/CVERecord?id=CVE-2018-4181 Référence CVE CVE-2018-4700 https://www.cve.org/CVERecord?id=CVE-2018-4700 Référence CVE CVE-2018-5407 https://www.cve.org/CVERecord?id=CVE-2018-5407 Référence CVE CVE-2018-5683 https://www.cve.org/CVERecord?id=CVE-2018-5683 Référence CVE CVE-2018-5729 https://www.cve.org/CVERecord?id=CVE-2018-5729 Référence CVE CVE-2018-5730 https://www.cve.org/CVERecord?id=CVE-2018-5730 Référence CVE CVE-2018-6914 https://www.cve.org/CVERecord?id=CVE-2018-6914 Référence CVE CVE-2018-7191 https://www.cve.org/CVERecord?id=CVE-2018-7191 Référence CVE CVE-2018-7208 https://www.cve.org/CVERecord?id=CVE-2018-7208 Référence CVE CVE-2018-7550 https://www.cve.org/CVERecord?id=CVE-2018-7550 Référence CVE CVE-2018-7568 https://www.cve.org/CVERecord?id=CVE-2018-7568 Ré

Official advisory ↗
CERT-FR · French · CERTFR-2019-AVI-242Multiples vulnérabilités dans F5 BIG-IP

De multiples vulnérabilités ont été découvertes dans F5 BIG-IP. Certaines d'entre elles permettent à un attaquant de provoquer un déni de service à distance, un contournement de la politique de sécurité et une atteinte à la confidentialité des données.

Official advisory ↗
CERT-FR · French · CERTFR-2019-AVI-023Multiples vulnérabilités dans Oracle Sun Systems

g/CVERecord?id=CVE-2018-15909 Référence CVE CVE-2018-17183 https://www.cve.org/CVERecord?id=CVE-2018-17183 Référence CVE CVE-2018-19158 https://www.cve.org/CVERecord?id=CVE-2018-19158 Référence CVE CVE-2018-19628 https://www.cve.org/CVERecord?id=CVE-2018-19628 Référence CVE CVE-2018-3070 https://www.cve.org/CVERecord?id=CVE-2018-3070 Référence CVE CVE-2018-3247 https://www.cve.org/CVERecord?id=CVE-2018-3247 Référence CVE CVE-2018-3282 https://www.cve.org/CVERecord?id=CVE-2018-3282 Référence CVE CVE-2018-3639 https://www.cve.org/CVERecord?id=CVE-2018-3639 Référence CVE CVE-2018-3646 https://www.cve.org/CVERecord?id=CVE-2018-3646 Référence CVE CVE-2018-5407 https://www.cve.org/CVERecord?id=CVE-2018-5407 Référence CVE CVE-2018-6913 https://www.cve.org/CVERecord?id=CVE-2018-6913 Référence CVE CVE-2018-9918 https://www.cve.org/CVERecord?id=CVE-2018-9918 Référence CVE CVE-2019-2412 https://www.cve.org/CVERecord?id=CVE-2019-2412 Référence CVE CVE-2019-2437 https://www.cve.org/CVERecord?id=CVE-2019-2437 Référence CVE CVE-2019-2541 https://www.cve.org/CVERecord?id=CVE-2019-2541 Référence CVE CVE-2019-2543 https://www.cve.org/CVERecord?id=CVE-2019-2543 Référence CVE CVE-2019-2544 https://www.cve.org/CVERecord?id=CVE-2019-2544 Référence CVE CVE-2019-2545 https://www.cve.org/CVERecord?id=CVE-2019-2545 Ge

Official advisory ↗
CERT-FR · French · CERTFR-2018-AVI-607Multiples vulnérabilités dans Tenable Nessus

De multiples vulnérabilités ont été découvertes dans Tenable Nessus. Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2018-012363Simultaneous Multi-threading における観測可能な不一致に関する脆弱性

Simultaneous Multi-threading (SMT) には、観測可能な不一致に関する脆弱性が存在します。

Official advisory ↗
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
Processors supporting Simultaneous Multi-Threading: N/A
Fixed
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted. After installing the updated packages, the httpd daemon will be restarted automatically.
Action
Apply the fixed release for the affected product branch as recorded by Red Hat Product Security. Validate the exact product and build in the linked advisory before deployment.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 15 Nov 2018 · Last source change 5 Aug 2024, 05:33 UTC · CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2018-17177
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
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

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed from remediation: access.redhat.com/CVE-2018-5407 to advisory no longer present in the provider's current catalogue.
    Before
    remediation: access.redhat.com/CVE-2018-5407
    After
    advisory no longer present in the provider's current catalogue
    Red Hat Product Security ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    N/A · 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.
    After
    N/A · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted. After installing the updated packages, the httpd daemon will be restarted automatically.
    Red Hat Product Security ↗
  3. ENISA EUVD mappingEUVD-2018-17177 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2018-17177"}
    ENISA EUVD ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: added patch: oracle.com/cpuapr2019-5072813.html; added patch: oracle.com/cpuapr2020.html; removed vendor advisory: access.redhat.com/RHSA-2019:0483; removed vendor advisory: access.redhat.com/RHSA-2019:0651; 4 further additions; 11 further removals.
    Before
    vendor advisory: access.redhat.com/RHSA-2019:0483 · vendor advisory: access.redhat.com/RHSA-2019:0651 · vendor advisory: access.redhat.com/RHSA-2019:0652 · 10 more references
    After
    patch: oracle.com/cpuapr2019-5072813.html · patch: oracle.com/cpuapr2020.html · patch: oracle.com/cpujan2019-5072801.html · 3 more references
    oracle.com ↗
  5. Affected versionsThe structured affected or fixed version information changed.
    Before
    N/A · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    N/A · 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.
    CNA ↗
  6. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    oracle.com ↗
  7. SeveritySeverity changed from Unknown to Medium.
    Before
    Unknown
    After
    Medium
    NIST NVD ↗
  8. CVSS scoreCVSS score changed from not recorded to 4.7 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N).
    Before
    not recorded
    After
    4.7 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N)
    NIST NVD ↗
  9. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2018-17177↗Red Hat Product Security security advisory↗Patch or update reference↗Patch or update reference↗Patch or update reference↗Patch or update reference↗CVE authority or vendor reference · Red Hat RHSA-2019:0483↗Public exploit reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗
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.
Free version - for non-commercial use only.CVE-2018-5407 · cve.blacktree.nl