CVE-2021-47325

Service interruption via leaked SMMU references

Published May 21, 2024 · Updated May 11, 2026

Resource leak in the ARM SMMU driver in Linux allows local users to interrupt service via address translation error paths. arm_smmu_iova_to_phys_hard returns from several timeout, translation-fault, and runtime-power failure paths without releasing the reference acquired by arm_smmu_rpm_get. Exploitation requires local low-privileged access and an affected ARM SMMU configuration; repeated failures consume references and impair availability.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource leak in the ARM SMMU driver in Linux allows local users to interrupt service via address translation error paths. arm_smmu_iova_to_phys_hard returns from several timeout, translation-fault, and runtime-power failure paths without releasing the reference acquired by arm_smmu_rpm_get. Exploitation requires local low-privileged access and an affected ARM SMMU configuration; repeated failures consume references and impair availability.

The record

CVE
CVE-2021-47325
Published
May 21, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 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=5.0
  2. Affected versionversion=d4a44f0750bb9bf7c44c22444a482756b2344a79 <0f0c5ea09139777d90729d408b807021f2ea6492
  3. Affected versionversion=d4a44f0750bb9bf7c44c22444a482756b2344a79 <43d1aaa1965f9b58035196dac49b1e1e6c9c25eb
  4. Affected versionversion=d4a44f0750bb9bf7c44c22444a482756b2344a79 <5f9741a9a91f25c89e04b408cd61e3ab050ce24b
  5. Affected versionversion=d4a44f0750bb9bf7c44c22444a482756b2344a79 <7c8f176d6a3fa18aa0f8875da6f7c672ed2a8554
  6. Affected versionversion=d4a44f0750bb9bf7c44c22444a482756b2344a79 <b11220803ad14a2a880cc06d8e01fe2548cc85b0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.0; version=d4a44f0750bb9bf7c44c22444a482756b2344a79 <0f0c5ea09139777d90729d408b807021f2ea6492; version=d4a44f0750bb9bf7c44c22444a482756b2344a79 <43d1aaa1965f9b58035196dac49b1e1e6c9c25eb; version=d4a44f0750bb9bf7c44c22444a482756b2344a79 <5f9741a9a91f25c89e04b408cd61e3ab050ce24b; version=d4a44f0750bb9bf7c44c22444a482756b2344a79 <7c8f176d6a3fa18aa0f8875da6f7c672ed2a8554; version=d4a44f0750bb9bf7c44c22444a482756b2344a79 <b11220803ad14a2a880cc06d8e01fe2548cc85b0

Published CVSS scores

3.3SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
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

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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