CVE-2021-47473

Service interruption via incorrect ELS cleanup condition

Published May 22, 2024 · Updated May 11, 2026

Memory-management error in the qla2xxx SCSI driver in Linux allows local users to interrupt service through a crafted FC BSG ELS request. The qla2x00_process_els function tests msgcode for equality with FC_BSG_RPT_ELS where inequality is required, selecting cleanup that leaks an fcport object or frees unallocated memory. Exploitation requires local low-privileged access to the Fibre Channel BSG path on a system using the qla2xxx driver; successful triggering can exhaust kernel memory or destabilize the host.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-management error in the qla2xxx SCSI driver in Linux allows local users to interrupt service through a crafted FC BSG ELS request. The qla2x00_process_els function tests msgcode for equality with FC_BSG_RPT_ELS where inequality is required, selecting cleanup that leaks an fcport object or frees unallocated memory. Exploitation requires local low-privileged access to the Fibre Channel BSG path on a system using the qla2xxx driver; successful triggering can exhaust kernel memory or destabilize the host.

The record

CVE
CVE-2021-47473
Published
May 22, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record 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=3.11
  2. Affected versionversion=8c0eb596baa51f2b43949c698c644727ef17805c <7fb223d0ad801f633c78cbe42b1d1b55f5d163ad
  3. Affected versionversion=8c0eb596baa51f2b43949c698c644727ef17805c <96f0aebf29be25254fa585af43924e34aa21fd9a
  4. Affected versionversion=8c0eb596baa51f2b43949c698c644727ef17805c <a7fbb56e6c941d9f59437b96412a348e66388d3e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.11; version=8c0eb596baa51f2b43949c698c644727ef17805c <7fb223d0ad801f633c78cbe42b1d1b55f5d163ad; version=8c0eb596baa51f2b43949c698c644727ef17805c <96f0aebf29be25254fa585af43924e34aa21fd9a; version=8c0eb596baa51f2b43949c698c644727ef17805c <a7fbb56e6c941d9f59437b96412a348e66388d3e

Published CVSS scores

5.5NIST NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

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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