CVE-2023-2020Network attack vector

Unauthorized downtime scheduling via missing access checks

Published Apr 18, 2023 · Updated Feb 5, 2025

Incorrect authorization in Checkmk 2.1.0 through 2.1.0p27 and 2.2.0 through 2.2.0b4 allows remote authenticated users to schedule downtimes. The REST API service-downtime handler failed to enforce both the wato.downtimes permission and access to the targeted host and service. Any account able to reach the authenticated API could suppress monitoring for services outside its authorized scope, without changing the underlying service.

CVSS severity4.3
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Incorrect authorization in Checkmk 2.1.0 through 2.1.0p27 and 2.2.0 through 2.2.0b4 allows remote authenticated users to schedule downtimes. The REST API service-downtime handler failed to enforce both the wato.downtimes permission and access to the targeted host and service. Any account able to reach the authenticated API could suppress monitoring for services outside its authorized scope, without changing the underlying service.

The record

CVE
CVE-2023-2020
Published
Apr 18, 2023
Updated
Feb 5, 2025
Vendor
Checkmk GmbH
Product
Checkmk
Classifications
CWE-863, CWE-280, T1562.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 5, 2025Record 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=2.1.0 <=2.1.0p27
  2. Affected versionversion=2.2.0 <=2.2.0b4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Checkmk GmbH · Checkmkversion=2.1.0 <=2.1.0p27; version=2.2.0 <=2.2.0b4

Published CVSS scores

4.3Checkmk GmbHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/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 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-863Incorrect Authorization
CWE-280Improper Handling of Insufficient Permissions or Privileges
T1562.001Impair Defenses: Disable or Modify Tools

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo