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Linux KernelOperating system · Linux

CVE-2021-3659

MEDIUM · 5.5 CVSS v3.1 Published 2022-08-22
Fix available
A fix is available. Upgrade to 5.12 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A NULL pointer dereference flaw was found in the Linux kernel’s IEEE 802.15.4 wireless networking subsystem in the way the user closes the LR-WPAN connection. This flaw allows a local user to crash the system. The highest threat from this vulnerability is to system availability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:< 5.12
FedoraOperating system
Affected:= 34
Enterprise LinuxOperating system
Affected:= 7.0= 8.0
Enterprise Linux For Ibm Z SystemsOperating system
Affected:= 8.0
Enterprise Linux For Ibm Z Systems EusOperating system
Affected:= 8.6
Enterprise Linux For Power Little Endian EusOperating system
Affected:= 8.6
Enterprise Linux For Real TimeOperating system
Affected:= 8.0
Enterprise Linux For Real Time For NfvOperating system
Affected:= 8.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.12 or later
Fixed in 5.12
Vendor patch bugzilla.redhat.com →
Recommended fix Moderate confidence

Linux Kernel 5.12 or later; or the latest available kernel update for your distribution

  1. Identify the current kernel version running on the affected system using `uname -r`
  2. For Fedora 34 systems: Update the kernel package by running `dnf update kernel` followed by a system reboot
  3. For RHEL/Enterprise Linux systems: Run `yum update kernel` or `dnf update kernel` to install the fixed kernel package
  4. After the kernel update is complete, reboot the system to load the new kernel: `systemctl reboot`
  5. Verify the system is running the updated kernel using `uname -r` and confirm the version is 5.12 or later
Caveat Kernel upgrades may require updates to kernel modules or drivers; ensure compatibility with critical applications before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-3659 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data