CVE-2021-47053

Local service interruption via unreleased hash padding

Published Feb 28, 2024 · Updated May 11, 2026

Memory leak in the sun8i-ss hash driver in Linux 5.10 allows local users to interrupt service through failed hash requests. The sun8i_ss_hash_run() function allocates a padding buffer but returns from several error paths without freeing it. Access to the Allwinner sun8i Security System hash accelerator is required; repeated failures retain kernel memory until service is interrupted.

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

Memory leak in the sun8i-ss hash driver in Linux 5.10 allows local users to interrupt service through failed hash requests. The sun8i_ss_hash_run() function allocates a padding buffer but returns from several error paths without freeing it. Access to the Allwinner sun8i Security System hash accelerator is required; repeated failures retain kernel memory until service is interrupted.

The record

CVE
CVE-2021-47053
Published
Feb 28, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 28, 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 <2c67a9333da9d0a3b87310e0d116b7c9070c7b00
  3. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <50274b01ac1689b1a3f6bc4b5b3dbf361a55dd3a
  4. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <c633e025bd04f54d7b33331cfcdb71354b08ce59
  5. Affected versionversion=d9b45418a91773b7672e4c60037a28074b495c6d <d3d702084d125689edb2b9395c707e09b471352e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=d9b45418a91773b7672e4c60037a28074b495c6d <2c67a9333da9d0a3b87310e0d116b7c9070c7b00; version=d9b45418a91773b7672e4c60037a28074b495c6d <50274b01ac1689b1a3f6bc4b5b3dbf361a55dd3a; version=d9b45418a91773b7672e4c60037a28074b495c6d <c633e025bd04f54d7b33331cfcdb71354b08ce59; version=d9b45418a91773b7672e4c60037a28074b495c6d <d3d702084d125689edb2b9395c707e09b471352e

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
T1499.004Application or System Exploitation

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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