BlackTreeCVE Intelligence
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Full vulnerability report · 2019
CVE-2018-20784High confidence

n/a: Loop with Unreachable Exit Condition ('Infinite Loop')

n/a · n/a

9.8CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
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.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 11 Sept 2026
Optional official sources

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

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

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-2018-13327

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 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

What

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

Why

A malformed condition prevents a loop from making progress or terminating, allowing resource exhaustion.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

Why

A malformed condition prevents a loop from making progress or terminating, allowing resource exhaustion.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

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.
None recorded

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
a network path → Loop with Unreachable Exit Condition ('Infinite Loop') → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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-835

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'). The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing 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.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-835
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2023-AVI-0664Multiples vulnérabilités dans le noyau Linux de SUSE

su-20233318-1/ Bulletin de sécurité SUSE SUSE-SU-2023:3324-1 du 16 août 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20233324-1/ Bulletin de sécurité SUSE SUSE-SU-2023:3329-1 du 16 août 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20233329-1/ Bulletin de sécurité SUSE SUSE-SU-2023:3333-1 du 16 août 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20233333-1/ Bulletin de sécurité SUSE SUSE-SU-2023:3349-1 du 17 août 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20233349-1/ Référence CVE CVE-2017-18344 https://www.cve.org/CVERecord?id=CVE-2017-18344 Référence CVE CVE-2018-20784 https://www.cve.org/CVERecord?id=CVE-2018-20784 Référence CVE CVE-2018-3639 https://www.cve.org/CVERecord?id=CVE-2018-3639 Référence CVE CVE-2022-40982 https://www.cve.org/CVERecord?id=CVE-2022-40982 Référence CVE CVE-2022-45919 https://www.cve.org/CVERecord?id=CVE-2022-45919 Référence CVE CVE-2023-0459 https://www.cve.org/CVERecord?id=CVE-2023-0459 Référence CVE CVE-2023-1637 https://www.cve.org/CVERecord?id=CVE-2023-1637 Référence CVE CVE-2023-1829 https://www.cve.org/CVERecord?id=CVE-2023-1829 Référence CVE CVE-2023-20569 https://www.cve.org/CVERecord?id=CVE-2023-20569 Référence CVE CVE-2023-20593 https://www.cve.org/CVERecord?id=CVE-2023

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0544Multiples vulnérabilités dans le noyau Linux de SUSE

4-1/ Bulletin de sécurité SUSE SUSE-SU-2023:2805-1 du 11 juillet 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20232805-1/ Bulletin de sécurité SUSE SUSE-SU-2023:2808-1 du 11 juillet 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20232808-1/ Bulletin de sécurité SUSE SUSE-SU-2023:2809-1 du 11 juillet 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20232809-1/ Bulletin de sécurité SUSE SUSE-SU-2023:2810-1 du 12 juillet 2023 https://www.suse.com/support/update/announcement/2023/suse-su-20232810-1/ Référence CVE CVE-2017-5753 https://www.cve.org/CVERecord?id=CVE-2017-5753 Référence CVE CVE-2018-20784 https://www.cve.org/CVERecord?id=CVE-2018-20784 Référence CVE CVE-2020-24588 https://www.cve.org/CVERecord?id=CVE-2020-24588 Référence CVE CVE-2022-2196 https://www.cve.org/CVERecord?id=CVE-2022-2196 Référence CVE CVE-2022-3523 https://www.cve.org/CVERecord?id=CVE-2022-3523 Référence CVE CVE-2022-3566 https://www.cve.org/CVERecord?id=CVE-2022-3566 Référence CVE CVE-2022-36280 https://www.cve.org/CVERecord?id=CVE-2022-36280 Référence CVE CVE-2022-38096 https://www.cve.org/CVERecord?id=CVE-2022-38096 Référence CVE CVE-2022-4269 https://www.cve.org/CVERecord?id=CVE-2022-4269 Référence CVE CVE-2022-45884 https://www.cve.org/CVERecord?id=CVE-2022

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-555Multiples vulnérabilités dans le noyau Linux de SUSE

su-20222079- du 14 juin 2022 https://www.suse.com/support/update/announcement/2022/suse-su-20222079-1/ Bulletin de sécurité le noyau Linux de SUSE suse-su-20222080- du 14 juin 2022 https://www.suse.com/support/update/announcement/2022/suse-su-20222080-1/ Bulletin de sécurité le noyau Linux de SUSE suse-su-20222082- du 14 juin 2022 https://www.suse.com/support/update/announcement/2022/suse-su-20222082-1/ Bulletin de sécurité le noyau Linux de SUSE suse-su-20222083- du 14 juin 2022 https://www.suse.com/support/update/announcement/2022/suse-su-20222083-1/ Référence CVE CVE-2017-13695 https://www.cve.org/CVERecord?id=CVE-2017-13695 Référence CVE CVE-2018-20784 https://www.cve.org/CVERecord?id=CVE-2018-20784 Référence CVE CVE-2018-7755 https://www.cve.org/CVERecord?id=CVE-2018-7755 Référence CVE CVE-2019-19377 https://www.cve.org/CVERecord?id=CVE-2019-19377 Référence CVE CVE-2019-20811 https://www.cve.org/CVERecord?id=CVE-2019-20811 Référence CVE CVE-2020-10769 https://www.cve.org/CVERecord?id=CVE-2020-10769 Référence CVE CVE-2021-20292 https://www.cve.org/CVERecord?id=CVE-2021-20292 Référence CVE CVE-2021-20321 https://www.cve.org/CVERecord?id=CVE-2021-20321 Référence CVE CVE-2021-28688 https://www.cve.org/CVERecord?id=CVE-2021-28688 Référence CVE CVE-2021-33061 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2019-AVI-419Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2018-14613 Référence CVE CVE-2018-14614 https://www.cve.org/CVERecord?id=CVE-2018-14614 Référence CVE CVE-2018-14615 https://www.cve.org/CVERecord?id=CVE-2018-14615 Référence CVE CVE-2018-14616 https://www.cve.org/CVERecord?id=CVE-2018-14616 Référence CVE CVE-2018-14617 https://www.cve.org/CVERecord?id=CVE-2018-14617 Référence CVE CVE-2018-16862 https://www.cve.org/CVERecord?id=CVE-2018-16862 Référence CVE CVE-2018-19985 https://www.cve.org/CVERecord?id=CVE-2018-19985 Référence CVE CVE-2018-20169 https://www.cve.org/CVERecord?id=CVE-2018-20169 Référence CVE CVE-2018-20511 https://www.cve.org/CVERecord?id=CVE-2018-20511 Référence CVE CVE-2018-20784 https://www.cve.org/CVERecord?id=CVE-2018-20784 Référence CVE CVE-2018-20856 https://www.cve.org/CVERecord?id=CVE-2018-20856 Référence CVE CVE-2018-5383 https://www.cve.org/CVERecord?id=CVE-2018-5383 Référence CVE CVE-2019-0136 https://www.cve.org/CVERecord?id=CVE-2019-0136 Référence CVE CVE-2019-10126 https://www.cve.org/CVERecord?id=CVE-2019-10126 Référence CVE CVE-2019-10207 https://www.cve.org/CVERecord?id=CVE-2019-10207 Référence CVE CVE-2019-10638 https://www.cve.org/CVERecord?id=CVE-2019-10638 Référence CVE CVE-2019-10639 https://www.cve.org/CVERecord?id=CVE-2019-10639 Référence CVE CVE-2019-11085 https://www.cve.org/CVERecord?id=CVE-

Official advisory ↗
CERT-FR · French · CERTFR-2019-AVI-361Multiples vulnérabilités dans le noyau Linux de Red Hat

De multiples vulnérabilités ont été découvertes dans le noyau Linux de Red Hat. Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une élévation de privilèges et un déni de service à distance.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2018-014607Linux Kernel におけるリソースの枯渇に関する脆弱性

Linux Kernel には、リソースの枯渇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
n/a: 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.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 22 Feb 2019 · Last source change 5 Aug 2024, 12:12 UTC · CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')

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-2018-13327
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2018-13327 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2018-13327"}
    ENISA EUVD
  2. Vendor guidanceAuthoritative vendor guidance changed from vendor advisory to authoritative remediation link · patch, vendor advisory.
    Before
    vendor advisory
    After
    authoritative remediation link · patch, vendor advisory
    af854a3a-2127-422b-91ae-364da2661108
  3. 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
  4. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    af854a3a-2127-422b-91ae-364da2661108
  5. SeveritySeverity changed from Unknown to Critical.
    Before
    Unknown
    After
    Critical
    NIST NVD
  6. CVSS scoreCVSS score changed from not recorded to 9.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
    Before
    not recorded
    After
    9.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
    NIST NVD
  7. Catalogue recordCVE added to the BlackTree catalogue.
    CNA
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
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-2018-20784 · cve.blacktree.nl