CVE-2023-30437Network attack vector

Username enumeration via HTTP 204 response discrepancy

Published Aug 27, 2023 · Updated Oct 1, 2024

Information disclosure in IBM Security Guardium 11.3, 11.4, and 11.5 allows remote attackers to enumerate usernames via crafted HTTP requests. The web interface produces a distinguishable HTTP 204 response for crafted requests, but IBM has not disclosed the affected endpoint or comparison logic. No authentication or user interaction is required, and the reported consequence is limited to disclosure of valid account names.

CVSS severity5.3
Medium
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in IBM Security Guardium 11.3, 11.4, and 11.5 allows remote attackers to enumerate usernames via crafted HTTP requests. The web interface produces a distinguishable HTTP 204 response for crafted requests, but IBM has not disclosed the affected endpoint or comparison logic. No authentication or user interaction is required, and the reported consequence is limited to disclosure of valid account names.

The record

CVE
CVE-2023-30437
Published
Aug 27, 2023
Updated
Oct 1, 2024
Vendor
IBM
Product
IBM Security Guardium
Classifications
T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 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=11.3
  2. Affected versionversion=11.3, 11.4, 11.5
  3. Affected versionversion=11.4
  4. Affected versionversion=11.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · IBM Security Guardiumversion=11.3; version=11.3, 11.4, 11.5; version=11.4; version=11.5

Published CVSS scores

5.3IBMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1087Account Discovery

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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