CVE-2021-47554

Local denial of service via uninitialized IOVA cleanup

Published May 24, 2024 · Updated May 11, 2026

Use of an uninitialized resource in Linux kernel 5.13 through 5.15.5 allows local users to crash the system via vDPA simulator creation. If vdpasim_create() fails before IOVA setup, vdpasim_free() calls put_iova_domain() on an uninitialized object and can also call iova_cache_put() without a prior iova_cache_get(). Triggering the fault requires local privileges sufficient to create a vDPA simulator device; the bounded consequence is a host kernel crash, and 5.16-rc1 and 5.16-rc2 are also affected.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of an uninitialized resource in Linux kernel 5.13 through 5.15.5 allows local users to crash the system via vDPA simulator creation. If vdpasim_create() fails before IOVA setup, vdpasim_free() calls put_iova_domain() on an uninitialized object and can also call iova_cache_put() without a prior iova_cache_get(). Triggering the fault requires local privileges sufficient to create a vDPA simulator device; the bounded consequence is a host kernel crash, and 5.16-rc1 and 5.16-rc2 are also affected.

The record

CVE
CVE-2021-47554
Published
May 24, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-908
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=4080fc1067501707b9693b8003feae7d50d14e35 <bb93ce4b150dde79f58e34103cbd1fe829796649
  2. Affected versionversion=4080fc1067501707b9693b8003feae7d50d14e35 <e4d58ac67e63727aa45a4a26185876f598e8b3dd
  3. Affected versionversion=5.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4080fc1067501707b9693b8003feae7d50d14e35 <bb93ce4b150dde79f58e34103cbd1fe829796649; version=4080fc1067501707b9693b8003feae7d50d14e35 <e4d58ac67e63727aa45a4a26185876f598e8b3dd; version=5.13

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.

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource

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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