CVE-2021-29727

Local kernel denial of service

Published Aug 26, 2021 · Updated Sep 17, 2024

Denial of service in the AIX kernel in IBM AIX 7.1 and 7.2 and VIOS 3.1 allows local users to interrupt system availability. IBM has not published the vulnerable kernel path, trigger, or operation responsible for the availability loss. The flaw requires local execution, but IBM has not disclosed whether successful exploitation crashes, hangs, or reboots the system.

CVSS severity6.2
Medium
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

Denial of service in the AIX kernel in IBM AIX 7.1 and 7.2 and VIOS 3.1 allows local users to interrupt system availability. IBM has not published the vulnerable kernel path, trigger, or operation responsible for the availability loss. The flaw requires local execution, but IBM has not disclosed whether successful exploitation crashes, hangs, or reboots the system.

The record

CVE
CVE-2021-29727
Published
Aug 26, 2021
Updated
Sep 17, 2024
Vendor
IBM
Product
AIX
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record 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=7.1
  2. Affected versionversion=7.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

IBM · AIXversion=7.1; version=7.2
IBM · PowerVM Virtual I/O Serverversion=3.1

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.2IBM CorporationCVSS:3.0/AV:L/AC:L/PR:N/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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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