CVE-2021-47205

System crash via stale CCU provider access

Published Apr 10, 2024 · Updated May 11, 2026

Use-after-unmap in Linux kernel 4.10 through 5.15.4 allows local users to crash the system by unbinding a sunxi-ng CCU driver. The unbind path unmaps the CCU MMIO region but leaves clock and reset providers registered, so later operations access unavailable MMIO. Local access and an affected sunxi-ng platform driver are required; a subsequent clock operation can page fault and interrupt the system.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-unmap in Linux kernel 4.10 through 5.15.4 allows local users to crash the system by unbinding a sunxi-ng CCU driver. The unbind path unmaps the CCU MMIO region but leaves clock and reset providers registered, so later operations access unavailable MMIO. Local access and an affected sunxi-ng platform driver are required; a subsequent clock operation can page fault and interrupt the system.

The record

CVE
CVE-2021-47205
Published
Apr 10, 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. Apr 10, 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=4.10
  2. Affected versionversion=c6a0637460c29799f1e63a6a4a65bda22caf4a54 <9bec2b9c6134052994115d2d3374e96f2ccb9b9d
  3. Affected versionversion=c6a0637460c29799f1e63a6a4a65bda22caf4a54 <b5dd513daa70ee8f6d281a20bd28485ee9bb7db2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.10; version=c6a0637460c29799f1e63a6a4a65bda22caf4a54 <9bec2b9c6134052994115d2d3374e96f2ccb9b9d; version=c6a0637460c29799f1e63a6a4a65bda22caf4a54 <b5dd513daa70ee8f6d281a20bd28485ee9bb7db2

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-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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