CVE-2021-3659Public exploit

System crash via invalid AEAD cleanup

Published Aug 22, 2022 · Updated Aug 3, 2024

NULL pointer dereference in the Linux kernel before 5.12 allows local users to crash the system through an LR-WPAN key operation. The llsec_key_alloc() error path treats failed or uninitialized AEAD transform entries as valid and passes them to crypto_free_aead(). The crash requires local access to the IEEE 802.15.4 key-add path and a transform setup failure; no confidentiality or integrity impact is reported.

CVSS severity5.5
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel before 5.12 allows local users to crash the system through an LR-WPAN key operation. The llsec_key_alloc() error path treats failed or uninitialized AEAD transform entries as valid and passes them to crypto_free_aead(). The crash requires local access to the IEEE 802.15.4 key-add path and a transform setup failure; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2021-3659
Published
Aug 22, 2022
Updated
Aug 3, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in Kernel 5.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Fixed in Kernel 5.12

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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