CVE-2021-38988

Local service interruption via undisclosed pfcdd flaw

Published Mar 7, 2022 · Updated Sep 17, 2024

Denial of service in IBM AIX 7.1 through 7.3 and PowerVM Virtual I/O Server 3.1 allows local users to interrupt a partition. The affected bos.pfcdd.rte fileset provides the pfcdd kernel extension, but IBM has not disclosed the erroneous operation or input that triggers the failure. A non-privileged local account is sufficient; IBM reports availability loss only and does not specify whether exploitation hangs, crashes, or reboots the partition.

CVSS severity6.2
Medium
EPSS probability0.22%
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 PowerVM Virtual I/O Server 3.1 allows local users to interrupt a partition. The affected bos.pfcdd.rte fileset provides the pfcdd kernel extension, but IBM has not disclosed the erroneous operation or input that triggers the failure. A non-privileged local account is sufficient; IBM reports availability loss only and does not specify whether exploitation hangs, crashes, or reboots the partition.

The record

CVE
CVE-2021-38988
Published
Mar 7, 2022
Updated
Sep 17, 2024
Vendor
IBM
Product
AIX
Classifications
T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 7, 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 privilegesunauthenticated

What is affected?

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

Published CVSS scores

6.2IBM CorporationCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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