CVE-2023-22359Network attack vector

Authenticated username enumeration via missing read-permission checks

Published Jun 26, 2023 · Updated Aug 28, 2024

User enumeration in the REST API of Checkmk 2.2.0 through 2.2.0p4 allows remote authenticated users to discover valid usernames. The user_config request schemas for create, edit, and delete operations fail to check user-read permission before processing a supplied username. Any authenticated account can probe these endpoints and learn which usernames exist, exposing account identifiers without gaining modification rights.

CVSS severity4.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

User enumeration in the REST API of Checkmk 2.2.0 through 2.2.0p4 allows remote authenticated users to discover valid usernames. The user_config request schemas for create, edit, and delete operations fail to check user-read permission before processing a supplied username. Any authenticated account can probe these endpoints and learn which usernames exist, exposing account identifiers without gaining modification rights.

The record

CVE
CVE-2023-22359
Published
Jun 26, 2023
Updated
Aug 28, 2024
Vendor
Checkmk GmbH
Product
Checkmk
Classifications
CWE-203, CAPEC-575, T1087
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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=2.2.0 <=2.2.0p4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Checkmk GmbH · Checkmkversion=2.2.0 <=2.2.0p4

Published CVSS scores

4.3Checkmk GmbHCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy
CAPEC-575Account Footprinting
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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