CVE-2021-47183

Driver unload hang via stale abort completion

Published Apr 10, 2024 · Updated Aug 5, 2026

NULL pointer dereference in the Linux lpfc SCSI driver allows adjacent attackers to hang driver unload by flapping an FC link. During link-down processing, the driver queues abort work requests before marking the link down, so a later completion can dereference an invalid ELS structure. Exploitation requires access to the adjacent FC or FCoE fabric and precisely timed link loss while PLOGIs remain outstanding; the bounded result is a driver-unload hang.

CVSS severity8.8
High
EPSS probability0.33%
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 lpfc SCSI driver allows adjacent attackers to hang driver unload by flapping an FC link. During link-down processing, the driver queues abort work requests before marking the link down, so a later completion can dereference an invalid ELS structure. Exploitation requires access to the adjacent FC or FCoE fabric and precisely timed link loss while PLOGIs remain outstanding; the bounded result is a driver-unload hang.

The record

CVE
CVE-2021-47183
Published
Apr 10, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 10, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=2.6.38
  2. Affected versionversion=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <04c1af683270e4709a594bb1691b8800b945035a
  3. Affected versionversion=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <1854f53ccd88ad4e7568ddfafafffe71f1ceb0a6
  4. Affected versionversion=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <28de48a7cea495ab48082d9ff4ef63f7cb4e563a

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.38; version=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <04c1af683270e4709a594bb1691b8800b945035a; version=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <1854f53ccd88ad4e7568ddfafafffe71f1ceb0a6; version=70f3c073362ef7b5e55c92b83eb2dd9a7fb4e9bf <28de48a7cea495ab48082d9ff4ef63f7cb4e563a

Published CVSS scores

8.8Linux kernel CVE teamCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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