CVE-2020-4267Network attack vector

Authenticated service interruption via LDAP memory leak

Published Apr 24, 2020 · Updated Sep 16, 2024

A memory leak in LDAP authentication in IBM MQ Appliance 8.0 and 9.1 allows remote authenticated users to interrupt service. The LDAP authentication code fails to release allocated memory during authenticated operations, allowing repeated activity to exhaust resources. LDAP authentication must be configured and valid credentials are required; the documented consequence is service interruption without data exposure or modification.

CVSS severity5.3
Medium
EPSS probability1.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory leak in LDAP authentication in IBM MQ Appliance 8.0 and 9.1 allows remote authenticated users to interrupt service. The LDAP authentication code fails to release allocated memory during authenticated operations, allowing repeated activity to exhaust resources. LDAP authentication must be configured and valid credentials are required; the documented consequence is service interruption without data exposure or modification.

The record

CVE
CVE-2020-4267
Published
Apr 24, 2020
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM MQ Appliance
Classifications
CWE-401, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.0.0.0
  2. Affected versionversion=8.0.0.1
  3. Affected versionversion=8.0.0.10
  4. Affected versionversion=8.0.0.11
  5. Affected versionversion=8.0.0.12
  6. Affected versionversion=8.0.0.13
  7. Affected versionversion=8.0.0.3
  8. Affected versionversion=8.0.0.4
  9. Affected versionversion=8.0.0.5
  10. Affected versionversion=8.0.0.6
  11. Affected versionversion=8.0.0.7
  12. Affected versionversion=8.0.0.8
  13. Affected versionversion=8.0.0.9
  14. Affected versionversion=9.1
  15. Affected versionversion=9.1.0.1
  16. Affected versionversion=9.1.0.2
  17. Affected versionversion=9.1.0.3
  18. Affected versionversion=9.1.0.4
  19. Affected versionversion=9.1.1
  20. Affected versionversion=9.1.2
  21. Affected versionversion=9.1.3
  22. Affected versionversion=9.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

IBM · IBM MQ Applianceversion=8.0.0.0; version=8.0.0.1; version=8.0.0.10; version=8.0.0.11; version=8.0.0.12; version=8.0.0.13; version=8.0.0.3; version=8.0.0.4; version=8.0.0.5; version=8.0.0.6; version=8.0.0.7; version=8.0.0.8; version=8.0.0.9; version=9.1; version=9.1.0.1; version=9.1.0.2; version=9.1.0.3; version=9.1.0.4; version=9.1.1; version=9.1.2; version=9.1.3; version=9.1.4

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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