CVE-2021-38994

Local denial of service via undisclosed kernel flaw

Published Feb 24, 2022 · Updated Sep 16, 2024

Kernel vulnerability in IBM AIX 7.1 through 7.3 and VIOS 3.1 allows local users to interrupt service through a denial of service. IBM has not published the vulnerable kernel function, triggering input, or failure mode beyond identifying the affected bos.mp64 fileset. Exploitation requires local non-privileged access; the documented consequence is loss of availability, with no 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 vulnerability in IBM AIX 7.1 through 7.3 and VIOS 3.1 allows local users to interrupt service through a denial of service. IBM has not published the vulnerable kernel function, triggering input, or failure mode beyond identifying the affected bos.mp64 fileset. Exploitation requires local non-privileged access; the documented consequence is loss of availability, with no reported data disclosure or modification.

The record

CVE
CVE-2021-38994
Published
Feb 24, 2022
Updated
Sep 16, 2024
Vendor
IBM
Product
AIX
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Feb 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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

2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
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

T1499Endpoint Denial of Service

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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