Cyber Resilience

CVE-2023-31211

Auth Bypass in Checkmk 2.0.0 … 2.2.0

Auth Bypass
Published
12 January 2024
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0051 41th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2023-31211 is a high-severity Incorrect Implementation of Authentication Algorithm (CWE-303) vulnerability in Checkmk Checkmk. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique External Remote Services (T1133); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

Insufficient authentication flow in Checkmk before 2.2.0p18, 2.1.0p38 and 2.0.0p39 allows attacker to use locked credentials

CWE(s)
CWE-303CWE-670

Related Threats

MITRE ATT&CK Enterprise Techniques

T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-0284Same product: Checkmk Checkmk
CVE-2023-22288Same product: Checkmk Checkmk
CVE-2023-31209Same product: Checkmk Checkmk
CVE-2023-31208Same product: Checkmk Checkmk
CVE-2023-22348Same product: Checkmk Checkmk
CVE-2023-6735Same product: Checkmk Checkmk
CVE-2023-1768Same product: Checkmk Checkmk
CVE-2023-6740Same product: Checkmk Checkmk
CVE-2023-6251Same product: Checkmk Checkmk
CVE-2025-39664Same product: Checkmk Checkmk

Affected Assets

checkmk
checkmk
2.0.0, 2.1.0, 2.2.0
tribe29
checkmk
≤ 2.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V9.2.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation at post-design stages directly uncovers incorrect implementations of required authentication algorithms.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development processes, standards, and tools reduces the chance that an established authentication algorithm is coded incorrectly.

SI-2 Flaw Remediation partial match

Flaw identification and remediation processes can locate and correct control-flow errors once they manifest as incorrect runtime behavior.

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.PS-06 mostly match
prevents

Secure SDLC practices directly require correct implementation of authentication algorithms.

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.8.5 Secure authentication full match
degrades

Secure authentication control directly requires correct implementation of authentication algorithms.

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

Security testing can detect flawed authentication implementations but does not prevent them by itself.

A.8.24 Use of cryptography partial match
degrades

Cryptography control addresses proper use of authentication algorithms but is broader than authentication alone.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle includes verification steps that can catch incorrect authentication implementations.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify correct authentication algorithm use but do not guarantee correct implementation.

A.8.28 Secure coding partial match
prevents

Secure coding practices reduce the likelihood of incorrect authentication algorithm implementation.

References