CVE-2021-38955

Service interruption via audit-command file creation flaw

Published Mar 1, 2022 · Updated Sep 16, 2024

Denial of service in IBM AIX 7.1 through 7.3 and VIOS 3.1 audit commands allows local users with elevated privileges to interrupt service. The affected audit commands mishandle file creation in the bos.rte.security fileset; IBM has not disclosed the specific command, path, or unsafe operation. Exploitation requires local elevated privileges and affects availability without reported confidentiality or integrity impact.

CVSS severity4.4
Medium
EPSS probability0.21%
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 IBM AIX 7.1 through 7.3 and VIOS 3.1 audit commands allows local users with elevated privileges to interrupt service. The affected audit commands mishandle file creation in the bos.rte.security fileset; IBM has not disclosed the specific command, path, or unsafe operation. Exploitation requires local elevated privileges and affects availability without reported confidentiality or integrity impact.

The record

CVE
CVE-2021-38955
Published
Mar 1, 2022
Updated
Sep 16, 2024
Vendor
IBM
Product
AIX
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 1, 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 privilegesadmin

What is affected?

IBM · AIXversion=7.1; version=7.2; version=7.3
IBM · PowerVM Virtual I/O Serverversion=3.1

Published CVSS scores

4.4IBMCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/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.

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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