CVE-2021-38995

Local kernel denial of service

Published Feb 24, 2022 · Updated Sep 17, 2024

Kernel denial of service in IBM AIX 7.1 through 7.3 and PowerVM VIOS 3.1 allows local users to interrupt the system via a kernel flaw. IBM identifies bos.mp64 as the affected fileset but has not published the kernel operation or input that triggers the failure. Non-privileged local access is required, and successful exploitation affects availability without reported data disclosure or modification.

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

Kernel denial of service in IBM AIX 7.1 through 7.3 and PowerVM VIOS 3.1 allows local users to interrupt the system via a kernel flaw. IBM identifies bos.mp64 as the affected fileset but has not published the kernel operation or input that triggers the failure. Non-privileged local access is required, and successful exploitation affects availability without reported data disclosure or modification.

The record

CVE
CVE-2021-38995
Published
Feb 24, 2022
Updated
Sep 17, 2024
Vendor
IBM
Product
AIX
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Feb 24, 2022CVE 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
  3. Affected versionversion=7.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

IBM · AIXversion=7.1; version=7.2; version=7.3
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
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P

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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