CVE-2021-47346

Kernel memory disclosure via out-of-bounds barrier-packet read

Published May 21, 2024 · Updated Aug 5, 2026

An out-of-bounds read in the Linux CoreSight TMC-ETF driver allows local users to disclose kernel memory through a perf AUX buffer. tmc_update_etf_buffer walks beyond the fixed-size coresight_barrier_pkt array because it omits the size check used by the related ETB path, copying adjacent kernel words until a zero value is encountered. A low-privileged per-task cs_etm session on ARM CoreSight ETF hardware is sufficient, and the invalid read can also fault the kernel.

CVSS severity7.1
High
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

An out-of-bounds read in the Linux CoreSight TMC-ETF driver allows local users to disclose kernel memory through a perf AUX buffer. tmc_update_etf_buffer walks beyond the fixed-size coresight_barrier_pkt array because it omits the size check used by the related ETB path, copying adjacent kernel words until a zero value is encountered. A low-privileged per-task cs_etm session on ARM CoreSight ETF hardware is sufficient, and the invalid read can also fault the kernel.

The record

CVE
CVE-2021-47346
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <0115687be7b13993066aef602253a53d55f5b11f
  2. Affected versionversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <04bd77ef4f4d9fc6102023b85f4590fc2130aac5
  3. Affected versionversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <35c1c4bd2d59ad734129d4e232af9d1098023918
  4. Affected versionversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <5fae8a946ac2df879caf3f79a193d4766d00239b
  5. Affected versionversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <733d4d95c0101d5f277b8e4910411d016e49a9dc
  6. Affected versionversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <ef0a06acc6b16388640ad367eedfa2a17f1945db
  7. Affected versionversion=4.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <0115687be7b13993066aef602253a53d55f5b11f; version=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <04bd77ef4f4d9fc6102023b85f4590fc2130aac5; version=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <35c1c4bd2d59ad734129d4e232af9d1098023918; version=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <5fae8a946ac2df879caf3f79a193d4766d00239b; version=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <733d4d95c0101d5f277b8e4910411d016e49a9dc; version=0c3fc4d5fa26092853278145aca9b21fa52a3e93 <ef0a06acc6b16388640ad367eedfa2a17f1945db; version=4.14

Published CVSS scores

7.1Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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-125Out-of-bounds Read

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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