CVE-2021-47501

Kernel crash via invalid VF VSI descriptor dump

Published May 24, 2024 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel i40e debugfs handler allows local users to crash the kernel through a VF VSI descriptor dump. The i40e_dbg_dump_desc handler accepts a VF VSI and reads its unavailable RX or TX ring pointers instead of rejecting a VSI type without descriptor rings. Triggering the fault requires local access to the i40e debugfs command path and an i40e SR-IOV VF VSI; the bounded consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.24%
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 i40e debugfs handler allows local users to crash the kernel through a VF VSI descriptor dump. The i40e_dbg_dump_desc handler accepts a VF VSI and reads its unavailable RX or TX ring pointers instead of rejecting a VSI type without descriptor rings. Triggering the fault requires local access to the i40e debugfs command path and an i40e SR-IOV VF VSI; the bounded consequence is a kernel crash.

The record

CVE
CVE-2021-47501
Published
May 24, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 24, 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=02e9c290814cc143ceccecb14eac3e7a05da745e <16431e442db248ecd8aa9457cf0a656f1885f56e
  2. Affected versionversion=02e9c290814cc143ceccecb14eac3e7a05da745e <23ec111bf3549aae37140330c31a16abfc172421
  3. Affected versionversion=02e9c290814cc143ceccecb14eac3e7a05da745e <e5b7fb2198abc50058f1a29c395b004f76ab1c83
  4. Affected versionversion=3.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=02e9c290814cc143ceccecb14eac3e7a05da745e <16431e442db248ecd8aa9457cf0a656f1885f56e; version=02e9c290814cc143ceccecb14eac3e7a05da745e <23ec111bf3549aae37140330c31a16abfc172421; version=02e9c290814cc143ceccecb14eac3e7a05da745e <e5b7fb2198abc50058f1a29c395b004f76ab1c83; version=3.12

Published CVSS scores

5.5Amazon LinuxCVSS: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-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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