CVE-2021-47059

Service interruption via leaked hash-result buffers

Published Feb 29, 2024 · Updated May 11, 2026

Memory leak in the Linux sun8i-ss hash driver versions 5.10 through 5.12.3 allows local users to interrupt service via hash requests. sun8i_ss_hash_run allocates a result buffer, but an error jumps to theend and finalizes the request without freeing that buffer. The flaw is reachable only on systems using the Allwinner Security System hash driver; repeated failed requests consume kernel memory without exposing or modifying data.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux sun8i-ss hash driver versions 5.10 through 5.12.3 allows local users to interrupt service via hash requests. sun8i_ss_hash_run allocates a result buffer, but an error jumps to theend and finalizes the request without freeing that buffer. The flaw is reachable only on systems using the Allwinner Security System hash driver; repeated failed requests consume kernel memory without exposing or modifying data.

The record

CVE
CVE-2021-47059
Published
Feb 29, 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. Feb 29, 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=5.10
  2. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <1dbc6a1e25be8575d6c4114d1d2b841a796507f7
  3. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <1f12aaf07f61122cf5074d29714ee26f8d44b0e7
  4. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <50e7b39b808430ad49a637dc6fb72ca93b451b13
  5. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <ca065a93699f8cf3f42c60eefed73086007e928e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=d9b45418a91773b7672e4c60037a28074b495c6d <1dbc6a1e25be8575d6c4114d1d2b841a796507f7; version=d9b45418a91773b7672e4c60037a28074b495c6d <1f12aaf07f61122cf5074d29714ee26f8d44b0e7; version=d9b45418a91773b7672e4c60037a28074b495c6d <50e7b39b808430ad49a637dc6fb72ca93b451b13; version=d9b45418a91773b7672e4c60037a28074b495c6d <ca065a93699f8cf3f42c60eefed73086007e928e

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.

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Technologies

Your stack

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Your stack

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