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CVE Record

CVE-2021-47494: cfg80211: fix management registrations locking

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel wireless networking bug. Incorrect locking around cfg80211 management registration lists can corrupt kernel data structures. The source bundle does not provide CVSS, severity, practical impact, exploit prerequisites, or evidence of active exploitation.

Executive priority

Treat as a patch-management item with uncertain urgency. Prioritize endpoint and embedded Linux fleets using wireless capabilities, but do not escalate as actively exploited based on the supplied evidence.

Technical view

cfg80211_mgmt_registrations_update() iterated management registration lists without holding all required spinlocks. The resolved fix moves locking to the wiphy/rdev level while keeping lists on each wdev, preventing cross-list corruption during updates.

Likely exposure

Likely relevant to Linux systems running affected kernel versions with cfg80211 wireless functionality present or used. The bundle lists affected Linux versions including 5.8, 5.10.77, 5.14.16, and 5.15, but does not define precise distro package exposure.

Exploitation context

CISA KEV status is false, and the provided sources do not claim active exploitation, public exploit availability, or weaponized use. The available evidence describes a kernel correctness issue and stable-branch fixes, not observed attacks.

Researcher notes

The record lacks CVSS, CWE, exploitability details, and privilege context. Analysis should focus on kernel version mapping, wireless stack reachability, and whether downstream distro kernels have backported the three referenced stable commits.

Mitigation direction

  • Check Linux distribution advisories for CVE-2021-47494 package status.
  • Update to a kernel package containing the referenced stable fixes.
  • Prioritize hosts using wireless networking or cfg80211-dependent functions.
  • Where patching is delayed, reduce unnecessary wireless functionality if operationally feasible.

Validation and detection

  • Inventory Linux kernel versions across laptops, servers, appliances, and embedded devices.
  • Confirm whether cfg80211 or wireless stack components are enabled or loaded.
  • Map installed distro kernel packages to vendor advisory fixed versions.
  • Review kernel changelogs for the referenced stable commits.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-47494 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d, 6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d, 6cd536fe62ef58d7c4eac2da07ab0ed7fd19010dunaffected
LinuxLinux5.8, 0, 5.10.77, 5.14.16, 5.15affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.