CVE-2020-4320
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 · uneditedIBM MQ Appliance and IBM MQ AMQP Channels 8.0, 9.0 LTS, 9.1 LTS, and 9.1 CD do not correctly block or allow clients based on the certificate distinguished name SSLPEER setting. IBM X-Force ID: 177403.
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 · high confidenceIBM MQ Appliance and AMQP Channels fail to correctly enforce client access controls based on the SSLPEER certificate distinguished name setting. This allows unauthorized clients to potentially connect or blocks legitimate clients when the SSLPEER DN filtering is misbehaving.
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>= 8.0.0.0, < 8.0.0.15>= 9.0.0.0, < 9.0.0.10>= 9.1.0, < 9.1.5>= 9.1.0.0, < 9.1.0.5CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify IBM MQ versionRun 'dspmqver -a' or check the queue manager version using 'runmqsc -m <QMGR> DISPLAY QMGR VERSION'Affected if The installed version falls within any of the affected ranges: 8.0.0.0-8.0.0.14, 9.0.0.0-9.0.0.9, 9.1.0-9.1.4, or 9.1.0.0-9.1.0.4
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Locate AMQP channelsUse runmqsc to query for AMQP channels: 'runmqsc -m <QMGR> DISPLAY CHANNEL(*) CHLTYPE(AMQP)'Affected if AMQP channels are defined and active on the queue manager, enabling the attack surface for this vulnerability
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Verify SSLPEER DN filtering configurationInspect channel definitions for SSLPEER settings using 'runmqsc -m <QMGR> DISPLAY CHANNEL(<AMQPChannel>) SSLPEER'Affected if SSLPEER certificate distinguished name filtering is configured on AMQP channels, as the flaw specifically affects DN-based access control enforcement
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Review AMQP connection logsExamine IBM MQ error logs (AMQERR01.LOG) and AMQP-specific logs for connection events, focusing on certificate authentication and any unexpected allow or deny patternsAffected if Connections are being allowed that should be blocked based on SSLPEER DN rules, or legitimate clients are being rejected despite valid certificate DNs
You are affected if running a vulnerable IBM MQ version with AMQP channels that use SSLPEER certificate DN filtering, and connection access patterns do not align with your intended SSLPEER rules.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor data8.0.0.159.0.0.109.1.0.5
Apply IBM security patches for CVE-2020-4320. In the interim, review alternative authentication mechanisms, implement additional network-level access controls, and verify client certificate mappings are functioning as intended.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-4320 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-4320 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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