CVE-2020-4320Network attack vector

Service interruption via faulty SSLPEER certificate filtering

Published Jun 16, 2020 · Updated Sep 16, 2024

Authorization error in IBM MQ AMQP Channels 8.0, 9.0 LTS, 9.1 LTS, and 9.1 CD allows remote authenticated users to interrupt service. An AMQP channel's SSLPEER logic incorrectly applies the configured certificate distinguished-name filter when accepting client certificates. A client certificate and an SSLPEER-restricted channel are required; successful abuse affects availability without reported data disclosure or modification.

CVSS severity5.3
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization error in IBM MQ AMQP Channels 8.0, 9.0 LTS, 9.1 LTS, and 9.1 CD allows remote authenticated users to interrupt service. An AMQP channel's SSLPEER logic incorrectly applies the configured certificate distinguished-name filter when accepting client certificates. A client certificate and an SSLPEER-restricted channel are required; successful abuse affects availability without reported data disclosure or modification.

The record

CVE
CVE-2020-4320
Published
Jun 16, 2020
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM MQ
Classifications
CWE-295, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 16, 2020CVE 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
  2. Affected versionversion=9.0.LTS
  3. Affected versionversion=9.1.CD
  4. Affected versionversion=9.1.LTS

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM MQversion=8.0; version=9.0.LTS; version=9.1.CD; version=9.1.LTS

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
5.3IBM CorporationCVSS:3.0/AV:N/AC:H/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

CWE-295Improper Certificate Validation
T1499Endpoint Denial of Service

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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