BlackTreeCVE Intelligence
← Back to the CVE catalogue
Full vulnerability report · 2024
CVE-2021-47494High confidence

cfg80211: fix management registrations locking

Linux · Linux

7.8HighCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 58 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Medium, lowered one band.downgradedsince 5 Aug 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.17% 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.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Linux Linux 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.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 58 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

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 · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.15.3-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.15.3-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.15.3-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcelinuxVendor fix publishedDebian records a fixed source-package version for this release.5.15.3-1Debian 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.

1 current
CVE-2021-47494 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykernel: cfg80211: fix management registrations locking
58 known affected

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

  • kernel as a component of Red Hat Enterprise Linux 6
  • kernel-abi-whitelists as a component of Red Hat Enterprise Linux 6
  • kernel-bootwrapper as a component of Red Hat Enterprise Linux 6
  • kernel-debug as a component of Red Hat Enterprise Linux 6
  • kernel-debug-devel as a component of Red Hat Enterprise Linux 6
  • kernel-devel as a component of Red Hat Enterprise Linux 6
  • kernel-doc as a component of Red Hat Enterprise Linux 6
  • kernel-firmware as a component of Red Hat Enterprise Linux 6
  • kernel-headers as a component of Red Hat Enterprise Linux 6
  • kernel-kdump as a component of Red Hat Enterprise Linux 6
  • kernel-kdump-devel as a component of Red Hat Enterprise Linux 6
  • kernel.src as a component of Red Hat Enterprise Linux 6
Summary
A vulnerability was found in the Linux kernel's `cfg80211` module, where improper locking of management registrations could lead to list corruption. This issue occurred because the `cfg80211_mgmt_registrations_update()` function iterated over a list without holding the correct spinlocks.
Remediation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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-2021-34498

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 actionPatch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 58 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: cfg80211: fix management registrations locking The management registrations locking was broken, the list was locked for each wdev, but cfg80211_mgmt_registrations_update() iterated it without holding all the correct spinlocks, causing list corruption. Rather than trying to fix it with fine-grained locking, just move the lock to the wiphy/rdev (still need the list on each wdev), we already need to hold the wdev lock to change it, so there's no contention on the lock in any case. This trivially fixes the bug since we hold one wdev's lock already, and now will hold the lock that protects all lists.

What

In the Linux kernel, the following vulnerability has been resolved: cfg80211: fix management registrations locking The management registrations locking was broken, the list was locked for each wdev, but cfg80211_mgmt_registrations_update() iterated it without holding all the correct spinlocks, causing list corruption. Rather than trying to fix it with fine-grained locking, just move the lock to the wiphy/rdev (still need the list on each wdev), we already need to hold the wdev lock to change it, so there's no contention on the lock in any case. This trivially fixes the bug since we hold one wdev's lock already, and now will hold the lock that protects all lists.

Why

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

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

In the Linux kernel, the following vulnerability has been resolved: cfg80211: fix management registrations locking The management registrations locking was broken, the list was locked for each wdev, but cfg80211_mgmt_registrations_update() iterated it without holding all the correct spinlocks, causing list corruption. Rather than trying to fix it with fine-grained locking, just move the lock to the wiphy/rdev (still need the list on each wdev), we already need to hold the wdev lock to change it, so there's no contention on the lock in any case. This trivially fixes the bug since we hold one wdev's lock already, and now will hold the lock that protects all lists.

Why

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

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.
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
local access → Improper Locking → 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-667 ↗

CWE-667: Improper Locking. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

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:H/A:H

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.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
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
CWE-667
A

Official authority intelligence

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

BSI · German · WID-SEC-2024-1197Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service und unspezifische Angriffe

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen oder unspezifische Angriffe durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20240529Security Bulletin 29 May 2024

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 29 May 2024, published on 29 May 2024. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0526Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47484 Référence CVE CVE-2021-47485 https://www.cve.org/CVERecord?id=CVE-2021-47485 Référence CVE CVE-2021-47486 https://www.cve.org/CVERecord?id=CVE-2021-47486 Référence CVE CVE-2021-47488 https://www.cve.org/CVERecord?id=CVE-2021-47488 Référence CVE CVE-2021-47489 https://www.cve.org/CVERecord?id=CVE-2021-47489 Référence CVE CVE-2021-47490 https://www.cve.org/CVERecord?id=CVE-2021-47490 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47492 https://www.cve.org/CVERecord?id=CVE-2021-47492 Référence CVE CVE-2021-47493 https://www.cve.org/CVERecord?id=CVE-2021-47493 Référence CVE CVE-2021-47494 https://www.cve.org/CVERecord?id=CVE-2021-47494 Référence CVE CVE-2021-47495 https://www.cve.org/CVERecord?id=CVE-2021-47495 Référence CVE CVE-2021-47496 https://www.cve.org/CVERecord?id=CVE-2021-47496 Référence CVE CVE-2021-47497 https://www.cve.org/CVERecord?id=CVE-2021-47497 Référence CVE CVE-2021-47498 https://www.cve.org/CVERecord?id=CVE-2021-47498 Référence CVE CVE-2021-47499 https://www.cve.org/CVERecord?id=CVE-2021-47499 Référence CVE CVE-2021-47500 https://www.cve.org/CVERecord?id=CVE-2021-47500 Référence CVE CVE-2021-47501 https://www.cve.org/CVERecord?id=CVE-2021-47501 Référence CVE CVE-2021-47502 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0496Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47484 Référence CVE CVE-2021-47485 https://www.cve.org/CVERecord?id=CVE-2021-47485 Référence CVE CVE-2021-47486 https://www.cve.org/CVERecord?id=CVE-2021-47486 Référence CVE CVE-2021-47488 https://www.cve.org/CVERecord?id=CVE-2021-47488 Référence CVE CVE-2021-47489 https://www.cve.org/CVERecord?id=CVE-2021-47489 Référence CVE CVE-2021-47490 https://www.cve.org/CVERecord?id=CVE-2021-47490 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47492 https://www.cve.org/CVERecord?id=CVE-2021-47492 Référence CVE CVE-2021-47493 https://www.cve.org/CVERecord?id=CVE-2021-47493 Référence CVE CVE-2021-47494 https://www.cve.org/CVERecord?id=CVE-2021-47494 Référence CVE CVE-2021-47495 https://www.cve.org/CVERecord?id=CVE-2021-47495 Référence CVE CVE-2021-47496 https://www.cve.org/CVERecord?id=CVE-2021-47496 Référence CVE CVE-2021-47497 https://www.cve.org/CVERecord?id=CVE-2021-47497 Référence CVE CVE-2021-47498 https://www.cve.org/CVERecord?id=CVE-2021-47498 Référence CVE CVE-2021-47499 https://www.cve.org/CVERecord?id=CVE-2021-47499 Référence CVE CVE-2021-47500 https://www.cve.org/CVERecord?id=CVE-2021-47500 Référence CVE CVE-2021-47501 https://www.cve.org/CVERecord?id=CVE-2021-47501 Référence CVE CVE-2021-47502 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-021984Linux の Linux Kernel におけるリソースのロックに関する脆弱性

Linux の Linux Kernel には、リソースのロック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.
Fix availability varies by product
Affected
Fixed
Linux: < 5.8, 5.10.77 ≤ 5.10.*, 5.14.16 ≤ 5.14.*, 5.15 ≤ *
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
04

Evidence and provenance

Published 22 May 2024 · Last source change 5 Aug 2026, 08:48 UTC · CWE-667 · Improper Locking

CVE recordCVE.org · 5.2
CVSS sourceCNA
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-2021-34498
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
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-2021-34498↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Patch or update reference↗Patch or update 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-2021-47494 · cve.blacktree.nl