BlackTreeIndependent security intelligence
← Back to the CVE catalogue
Full vulnerability report · 2021
CVE-2021-34693High confidence

net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized

n/a · n/a

5.5MediumCVSS 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
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 9 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-2021-21343

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

net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized.

What

net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized.

Why

The product does not initialize a critical resource.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.

What

net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized.

Why

The product does not initialize a critical resource.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may obtain information outside the intended access boundary.

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 → Missing Initialization of Resource → obtain information outside the intended access boundary
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-909 ↗

CWE-909: Missing Initialization of Resource. The product does not initialize a critical resource.

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:L/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.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.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-909Public exploit reference
A

Official authority intelligence

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

CERT-FR · French · CERTFR-2022-AVI-265Multiples vulnérabilités dans le noyau Linux de Ubuntu

d?id=CVE-2021-28713 Référence CVE CVE-2021-28714 https://www.cve.org/CVERecord?id=CVE-2021-28714 Référence CVE CVE-2021-28715 https://www.cve.org/CVERecord?id=CVE-2021-28715 Référence CVE CVE-2021-28972 https://www.cve.org/CVERecord?id=CVE-2021-28972 Référence CVE CVE-2021-29650 https://www.cve.org/CVERecord?id=CVE-2021-29650 Référence CVE CVE-2021-32399 https://www.cve.org/CVERecord?id=CVE-2021-32399 Référence CVE CVE-2021-33033 https://www.cve.org/CVERecord?id=CVE-2021-33033 Référence CVE CVE-2021-33034 https://www.cve.org/CVERecord?id=CVE-2021-33034 Référence CVE CVE-2021-33098 https://www.cve.org/CVERecord?id=CVE-2021-33098 Référence CVE CVE-2021-34693 https://www.cve.org/CVERecord?id=CVE-2021-34693 Référence CVE CVE-2021-3483 https://www.cve.org/CVERecord?id=CVE-2021-3483 Référence CVE CVE-2021-3506 https://www.cve.org/CVERecord?id=CVE-2021-3506 Référence CVE CVE-2021-3564 https://www.cve.org/CVERecord?id=CVE-2021-3564 Référence CVE CVE-2021-3573 https://www.cve.org/CVERecord?id=CVE-2021-3573 Référence CVE CVE-2021-3612 https://www.cve.org/CVERecord?id=CVE-2021-3612 Référence CVE CVE-2021-3679 https://www.cve.org/CVERecord?id=CVE-2021-3679 Référence CVE CVE-2021-38160 https://www.cve.org/CVERecord?id=CVE-2021-38160 Référence CVE CVE-2021-38198 https://www.cve.org/CVERecord?id=CVE-2021-381

Official advisory
CERT-FR · French · CERTFR-2022-AVI-176Multiples vulnérabilités dans le noyau Linux d'Ubuntu

rd?id=CVE-2021-0129 Référence CVE CVE-2021-22600 https://www.cve.org/CVERecord?id=CVE-2021-22600 Référence CVE CVE-2021-28711 https://www.cve.org/CVERecord?id=CVE-2021-28711 Référence CVE CVE-2021-28712 https://www.cve.org/CVERecord?id=CVE-2021-28712 Référence CVE CVE-2021-28713 https://www.cve.org/CVERecord?id=CVE-2021-28713 Référence CVE CVE-2021-28714 https://www.cve.org/CVERecord?id=CVE-2021-28714 Référence CVE CVE-2021-28715 https://www.cve.org/CVERecord?id=CVE-2021-28715 Référence CVE CVE-2021-28972 https://www.cve.org/CVERecord?id=CVE-2021-28972 Référence CVE CVE-2021-33034 https://www.cve.org/CVERecord?id=CVE-2021-33034 Référence CVE CVE-2021-34693 https://www.cve.org/CVERecord?id=CVE-2021-34693 Référence CVE CVE-2021-3483 https://www.cve.org/CVERecord?id=CVE-2021-3483 Référence CVE CVE-2021-3564 https://www.cve.org/CVERecord?id=CVE-2021-3564 Référence CVE CVE-2021-3612 https://www.cve.org/CVERecord?id=CVE-2021-3612 Référence CVE CVE-2021-3679 https://www.cve.org/CVERecord?id=CVE-2021-3679 Référence CVE CVE-2021-38204 https://www.cve.org/CVERecord?id=CVE-2021-38204 Référence CVE CVE-2021-39685 https://www.cve.org/CVERecord?id=CVE-2021-39685 Référence CVE CVE-2021-4083 https://www.cve.org/CVERecord?id=CVE-2021-4083 Référence CVE CVE-2021-4155 https://www.cve.org/CVERecord?id=CVE-2021-41

Official advisory
CERT-FR · French · CERTFR-2021-AVI-726Multiples vulnérabilités dans le noyau Linux d'Ubuntu

De multiples vulnérabilités ont été découvertes dans le noyau Linux d'Ubuntu. Elles permettent à un attaquant de provoquer une exécution de code arbitraire, un déni de service et une atteinte à la confidentialité des données.

Official advisory
CERT-FR · French · CERTFR-2021-AVI-695Multiples vulnérabilités dans le noyau Linux d'Ubuntu

De multiples vulnérabilités ont été découvertes dans le noyau Linux d'Ubuntu. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire, un déni de service et un contournement de la politique de sécurité.

Official advisory
CERT-FR · French · CERTFR-2021-AVI-635Multiples vulnérabilités dans le noyau Linux d'Ubuntu

De multiples vulnérabilités ont été découvertes dans le noyau Linux d'Ubuntu. Elles permettent à un attaquant de provoquer une exécution de code arbitraire, un déni de service et une atteinte à la confidentialité des données.

Official advisory
CERT-FR · French · CERTFR-2021-AVI-570Multiples vulnérabilités dans le noyau Linux de SUSE

Record?id=CVE-2021-0129 Référence CVE CVE-2021-0512 https://www.cve.org/CVERecord?id=CVE-2021-0512 Référence CVE CVE-2021-0605 https://www.cve.org/CVERecord?id=CVE-2021-0605 Référence CVE CVE-2021-22555 https://www.cve.org/CVERecord?id=CVE-2021-22555 Référence CVE CVE-2021-23133 https://www.cve.org/CVERecord?id=CVE-2021-23133 Référence CVE CVE-2021-23134 https://www.cve.org/CVERecord?id=CVE-2021-23134 Référence CVE CVE-2021-32399 https://www.cve.org/CVERecord?id=CVE-2021-32399 Référence CVE CVE-2021-33034 https://www.cve.org/CVERecord?id=CVE-2021-33034 Référence CVE CVE-2021-33909 https://www.cve.org/CVERecord?id=CVE-2021-33909 Référence CVE CVE-2021-34693 https://www.cve.org/CVERecord?id=CVE-2021-34693 Référence CVE CVE-2021-3609 https://www.cve.org/CVERecord?id=CVE-2021-3609 Gestion détaillée du document le 23 juillet 2021 Version initiale Alertes Avis Bulletins d’actualités Mentions légales Conditions générales À propos Contact cyber.gouv.fr service-public.fr legifrance.gouv.fr info.gouv.fr france.fr info.gouv.fr/risques Premier Ministre / Secrétariat Général de la Défense et de la Sécurité Nationale / Agence nationale de la sécurité des systèmes d'information

Official advisory
CERT-FR · French · CERTFR-2021-AVI-563Multiples vulnérabilités dans le noyau Linux de SUSE

rd?id=CVE-2021-0605 Référence CVE CVE-2021-22555 https://www.cve.org/CVERecord?id=CVE-2021-22555 Référence CVE CVE-2021-23133 https://www.cve.org/CVERecord?id=CVE-2021-23133 Référence CVE CVE-2021-23134 https://www.cve.org/CVERecord?id=CVE-2021-23134 Référence CVE CVE-2021-32399 https://www.cve.org/CVERecord?id=CVE-2021-32399 Référence CVE CVE-2021-33034 https://www.cve.org/CVERecord?id=CVE-2021-33034 Référence CVE CVE-2021-33200 https://www.cve.org/CVERecord?id=CVE-2021-33200 Référence CVE CVE-2021-33624 https://www.cve.org/CVERecord?id=CVE-2021-33624 Référence CVE CVE-2021-33909 https://www.cve.org/CVERecord?id=CVE-2021-33909 Référence CVE CVE-2021-34693 https://www.cve.org/CVERecord?id=CVE-2021-34693 Référence CVE CVE-2021-3491 https://www.cve.org/CVERecord?id=CVE-2021-3491 Référence CVE CVE-2021-35039 https://www.cve.org/CVERecord?id=CVE-2021-35039 Référence CVE CVE-2021-3573 https://www.cve.org/CVERecord?id=CVE-2021-3573 Référence CVE CVE-2021-3609 https://www.cve.org/CVERecord?id=CVE-2021-3609 Référence CVE CVE-2021-3612 https://www.cve.org/CVERecord?id=CVE-2021-3612 Référence CVE CVE-2020-24586 https://www.cve.org/CVERecord?id=CVE-2020-24586 Référence CVE CVE-2020-24587 https://www.cve.org/CVERecord?id=CVE-2020-24587 Référence CVE CVE-2020-24588 https://www.cve.org/CVERecord?id=CVE-2020

Official advisory
CERT-FR · French · CERTFR-2021-AVI-553Multiples vulnérabilités dans le noyau Linux de Debian

De multiples vulnérabilités ont été découvertes dans le noyau Linux de Debian et Debian LTS. Elles permettent à un attaquant de provoquer un déni de service, une atteinte à la confidentialité des données et une élévation de privilèges.

Official advisory
CERT-FR · French · CERTFR-2021-AVI-535Multiples vulnérabilités dans le noyau Linux de SUSE

De multiples vulnérabilités ont été découvertes dans le noyau Linux de SUSE. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire, un contournement de la politique de sécurité et une atteinte à l'intégrité des données.

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
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. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 14 Jun 2021 · Last source change 4 Aug 2024, 00:19 UTC · CWE-909 · Missing Initialization of Resource

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 2026-08-14
European sourceENISA EUVD · EUVD-2021-21343
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 →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2021-21343↗Public exploit reference↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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-2021-34693 · cve.blacktree.nl