CVE-2021-38875Network attack vector

Queue-manager denial of service via malformed messages

Published Nov 23, 2021 · Updated Sep 16, 2024

Denial of service in IBM MQ 8.0, 9.0 LTS, 9.1 LTS, 9.2 LTS, 9.1 CD, and 9.2 CD allows remote authenticated users to interrupt a queue manager. The message-processing code mishandles a malformed message, but IBM has not disclosed the specific parser or erroneous operation. Exploitation requires authority to connect to the queue manager and place messages, and the reported consequence is availability loss only.

CVSS severity6.5
Medium
EPSS probability1.01%
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 MQ 8.0, 9.0 LTS, 9.1 LTS, 9.2 LTS, 9.1 CD, and 9.2 CD allows remote authenticated users to interrupt a queue manager. The message-processing code mishandles a malformed message, but IBM has not disclosed the specific parser or erroneous operation. Exploitation requires authority to connect to the queue manager and place messages, and the reported consequence is availability loss only.

The record

CVE
CVE-2021-38875
Published
Nov 23, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM MQ
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 23, 2021CVE 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=8.0.0
  2. Affected versionversion=9.0.0
  3. Affected versionversion=9.1.0
  4. Affected versionversion=9.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM MQversion=8.0.0; version=9.0.0; version=9.1.0; version=9.2.0

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
6.5IBM CorporationCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5NIST NVDCVSS:3.1/AV:N/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.

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)
Vectornetwork
Privilegesauthenticated
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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