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MqApplication · Ibm

CVE-2021-39034

HIGH · 7.5 CVSS v3.1 Published 2022-02-17
Fix available
A fix is available. Upgrade to after 9.1.0.9 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
IBM MQ 9.1 LTS is vulnerable to a denial of service attack caused by an issue within the channel process. IBM X-Force ID: 213964.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

IBM MQ 9.1 LTS contains a denial of service vulnerability in the channel process component. An attacker can exploit this by sending malicious traffic to the channel process, causing the service to become unavailable.

MitigationApply the IBM MQ 9.1 LTS security patch for CVE-2021-39034. If immediate patching is not possible, restrict network access to MQ channel listeners using firewalls or ACLs to limit exposure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MqApplication
Affected:>= 9.1.0.0, <= 9.1.0.9

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed IBM MQ version
    Run the command 'dspmqver' on the MQ server to display the version information. Alternatively, check the installation directory /opt/mqm or the output of 'mqversion' if available.
    Affected if The version displayed is 9.1.0.0 through 9.1.0.9 (inclusive)
  2. Identify queue managers and their status
    Run 'dspmq' to list all queue managers and their current state. Note which queue managers are running.
    Affected if Any queue manager is running on a version in the affected range (9.1.0.0-9.1.0.9)
  3. Check for active channel listeners
    Connect to each running queue manager using 'runmqsc [qm_name]' and run the command 'LISTENER(*) ALL' to display all configured listeners and their ports/status.
    Affected if Channel listeners are configured and active on any queue manager using an affected version
  4. Verify channel listener network exposure
    Use 'netstat -an | grep [listener_port]' or 'ss -tlnp | grep [listener_port]' to check which ports the channel listeners are bound to and whether they are listening on external interfaces (0.0.0.0) vs localhost only (127.0.0.1).
    Affected if Channel listeners are bound to 0.0.0.0 or all interfaces, making them externally accessible

You are affected if any IBM MQ installation on your system runs version 9.1.0.0 through 9.1.0.9 with active channel listeners accessible over the network.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 9.1.0.9
Interim mitigation

Apply the IBM MQ 9.1 LTS security patch for CVE-2021-39034. If immediate patching is not possible, restrict network access to MQ channel listeners using firewalls or ACLs to limit exposure.

Recommended fix Moderate confidence

IBM MQ 9.1.0.10 or later (9.1 LTS Fix Pack 10)

  1. Verify current IBM MQ version by running 'dspmqver' command
  2. Review IBM MQ 9.1 LTS fix list at www.ibm.com/support/pages/node/6239384 or search for APAR IT36437 which addresses this vulnerability
  3. Upgrade to IBM MQ 9.1.0.10 or later (the first version that includes the fix for CVE-2021-39034)
  4. After upgrade, restart the queue manager and channel initiator processes to ensure the fix is active
  5. Verify the fix is applied by checking the channel process is no longer vulnerable to the DoS condition described in the security bulletin
Caveat No major breaking changes expected for this DoS fix; standard LTS upgrade procedures apply

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mq Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-39034 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data