CVE-2021-47153

Memory disclosure via bus-reset interrupt mishandling

Published Mar 25, 2024 · Updated Aug 5, 2026

Out-of-bounds read in the Linux i801 I2C driver allows local users to disclose kernel memory via timed-out block transactions. The i801_isr handler treats the KILL recovery interrupt as a completed transaction and advances block processing beyond its valid range. Reachability requires access to an exposed I2C adapter on supported Intel SMBus hardware; the faulty path can disclose kernel memory and interrupt service.

CVSS severity7.1
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux i801 I2C driver allows local users to disclose kernel memory via timed-out block transactions. The i801_isr handler treats the KILL recovery interrupt as a completed transaction and advances block processing beyond its valid range. Reachability requires access to an exposed I2C adapter on supported Intel SMBus hardware; the faulty path can disclose kernel memory and interrupt service.

The record

CVE
CVE-2021-47153
Published
Mar 25, 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. Mar 25, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.6
  2. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <04cc05e3716ae31b17ecdab7bc55c8170def1b8b
  3. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <09c9e79f4c10cfb6b9e0e1b4dd355232e4b5a3b3
  4. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <1f583d3813f204449037cd2acbfc09168171362a
  5. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <b523feb7e8e44652f92f3babb953a976e7ccbbef
  6. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <c70e1ba2e7e65255a0ce004f531dd90dada97a8c
  7. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <dfa8929e117b0228a7765f5c3f5988a4a028f3c6
  8. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <e4d8716c3dcec47f1557024add24e1f3c09eb24b
  9. Affected versionversion=636752bcb5177a301d0266270661581de8624828 <f9469082126cebb7337db3992d143f5e4edfe629

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.6; version=636752bcb5177a301d0266270661581de8624828 <04cc05e3716ae31b17ecdab7bc55c8170def1b8b; version=636752bcb5177a301d0266270661581de8624828 <09c9e79f4c10cfb6b9e0e1b4dd355232e4b5a3b3; version=636752bcb5177a301d0266270661581de8624828 <1f583d3813f204449037cd2acbfc09168171362a; version=636752bcb5177a301d0266270661581de8624828 <b523feb7e8e44652f92f3babb953a976e7ccbbef; version=636752bcb5177a301d0266270661581de8624828 <c70e1ba2e7e65255a0ce004f531dd90dada97a8c; version=636752bcb5177a301d0266270661581de8624828 <dfa8929e117b0228a7765f5c3f5988a4a028f3c6; version=636752bcb5177a301d0266270661581de8624828 <e4d8716c3dcec47f1557024add24e1f3c09eb24b; version=636752bcb5177a301d0266270661581de8624828 <f9469082126cebb7337db3992d143f5e4edfe629

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
6.0CISA-ADPCVSS:3.1/AV:L/AC:L/PR:H/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.

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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