Cyber Resilience

CVE-2023-2020

Access Control in Checkmk 2.1.0 … 2.2.0

Access Control
Published
18 April 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0040 33th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2023-2020 is a medium-severity Improper Handling of Insufficient Permissions or Privileges (CWE-280) vulnerability in Checkmk Checkmk. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access ControlA10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

Insufficient permission checks in the REST API in Tribe29 Checkmk <= 2.1.0p27 and <= 2.2.0b4 (beta) allow unauthorized users to schedule downtimes for any host.

CWE(s)
CWE-280CWE-863

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
attack.mitre.org →
T1548.002 Bypass User Account Control Privilege Escalation
Adversaries may bypass UAC mechanisms to elevate process privileges on system.
attack.mitre.org →
T1548.003 Sudo and Sudo Caching Privilege Escalation
Adversaries may perform sudo caching and/or use the sudoers file to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-3103Same product: Checkmk Checkmk
CVE-2024-8606Same product: Checkmk Checkmk
CVE-2026-7765Same product: Checkmk Checkmk
CVE-2025-64997Same product: Checkmk Checkmk
CVE-2026-24096Same product: Checkmk Checkmk
CVE-2025-58121Same product: Checkmk Checkmk
CVE-2025-58122Same product: Checkmk Checkmk
CVE-2024-28824Same product: Checkmk Checkmk
CVE-2024-28829Same product: Checkmk Checkmk
CVE-2023-23549Same product: Checkmk Checkmk

Affected Assets

checkmk
checkmk
2.1.0, 2.2.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 11 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.2
  • V8.3.3

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-1 Policy and Procedures
addresses: CWE-863

Periodic review and update of procedures reduces incorrect authorization implementations over time.

AC-13 Supervision and Review — Access Control
addresses: CWE-863

Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.

AC-16 Security and Privacy Attributes
addresses: CWE-863

Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.

AC-17 Remote Access
addresses: CWE-863

The authorization process and usage restrictions help prevent incorrect authorization for remote access types.

AC-18 Wireless Access
addresses: CWE-863

Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.

AC-19 Access Control for Mobile Devices
addresses: CWE-863

Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.

AC-2 Account Management
addresses: CWE-863

Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.

AC-20 Use of External Systems
addresses: CWE-863

Ensures authorization decisions for external system use are correctly implemented and enforced.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

Defining, enforcing and reviewing access permissions with least privilege directly prevents code paths that mishandle insufficient privileges.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data surfaces adverse events triggered by unhandled permission failures.

PR.PS-04 partial match
prevents

Generating logs of permission-related events enables detection and analysis of improper handling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect missing or incorrect privilege handling.

A.5.15 Access control partial match
prevents

Defines access-control policy that should prevent insufficient-privilege situations.

A.5.18 Access rights partial match
degrades

Specifies how access rights are granted, reviewed and revoked, directly addressing privilege handling.

A.8.2 Privileged access rights partial match
degrades

Requires explicit management of privileged access rights, reducing the chance of missing privilege checks.

A.8.25 Secure development life cycle partial match
prevents

Secure-SDLC practices include privilege checks during design and coding.

A.8.28 Secure coding partial match
prevents

Secure-coding standards require proper permission checks before resource access.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (4 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-863
  • V-248548 OL 8 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
  • V-248596 OL 8 must enable the SELinux targeted policy. prevents CWE-280
Oracle Linux 9 (1 rule)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
RHEL 7 (1 rule)
  • V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-863
RHEL 8 (1 rule)
  • V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-863
RHEL 9 (2 rules)
  • V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
  • V-272496 RHEL 9 must elevate the SELinux context when an administrator calls the sudo command. prevents CWE-280

References