Skip to main content

Checkmk CVE-2023-31211

HIGH
Incorrect Implementation of Authentication Algorithm (CWE-303)
2024-01-12 security@checkmk.com
8.8
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication algorithm review
Impact

CVSS score of 8.8 (HIGH). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. EPSS exploitation probability: 0.12%.

Exploit ScenarioDerived

This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.1% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 28, 2026

Insufficient authentication flow in Checkmk before 2.2.0p18, 2.1.0p38 and 2.0.0p39 allows attacker to use locked credentials. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity.

Earlier versions of this analysis (1)
v1 Mar 28, 2026 - 19:34 CVSS 8.8

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

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-303. Insufficient authentication flow in Checkmk before 2.2.0p18, 2.1.0p38 and 2.0.0p39 allows attacker to use locked credentials Affected products include: Checkmk, Tribe29 Checkmk. Version information: before 2.2.0.

Know when Checkmk gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 8.8 HIGH
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch released
Mar 28, 2026 - 19:34 nvd
Patch available
CVE Published
Jan 12, 2024 - 08:15 nvd
HIGH 8.8

DescriptionCVE.org

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

Executive ViewAI

Why It Matters

Organizations using Checkmk face significant risk from CVE-2023-31211 rated CVSS 8.8. Successful exploitation could significantly impact the confidentiality, integrity, or availability of affected systems. A patch is available and should be applied as part of regular vulnerability management.

Business Impact: Severe
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Implement network-level access controls to limit exposure; (2) Enable enhanced monitoring and alerting; (3) Apply principle of least privilege.

Threat Intelligence Overview

EPSS Score
0.1%
Top 69% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.1%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact
Very High

Priority Score

44
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +44
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)CVE.org

cpe:2.3:a:checkmk:checkmk:2.0.0:b1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b2:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b3:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b4:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b5:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b6:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b7:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:b8:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:i1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p1:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p10:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p11:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p12:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p13:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p14:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p15:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p16:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p17:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p18:*:*:*:*:*:*
cpe:2.3:a:checkmk:checkmk:2.0.0:p19:*:*:*:*:*:*
+ 98 more
CVE-2017-14955 MEDIUM POC
5.9 Oct 02

Check_MK before 1.2.8p26 mishandles certain errors within the failed-login save feature because of a race condition, whi

CVE-2021-40904 HIGH POC
8.8 Mar 25

The web management console of CheckMK Raw Edition (versions 1.5.0 to 1.6.0) allows a misconfiguration of the web-app Dok

CVE-2021-40905 HIGH POC
8.8 Mar 25

The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uplo

CVE-2025-32919 HIGH POC
8.8 Oct 09

Local privilege escalation in the Checkmk Windows Agent's Windows License plugin allows an authenticated low-privileged

CVE-2025-39663 HIGH POC
8.5 Oct 30

Stored/transmitted cross-site scripting in Checkmk's distributed monitoring lets an attacker who already controls a remo

CVE-2025-39664 HIGH POC
7.1 Oct 09

Authenticated path traversal in Checkmk's report scheduler lets a user with valid application credentials write report f

CVE-2024-28825 CRITICAL
9.8 Apr 24

Improper restriction of excessive authentication attempts on some authentication methods in Checkmk before 2.3.0b5 (beta

CVE-2021-36563 MEDIUM POC
5.4 Jul 26

The CheckMK management web console (versions 1.5.0 to 2.0.0) does not sanitise user input in various parameters of the W

CVE-2025-39666 CRITICAL
9.3 Apr 07

Local privilege escalation in Checkmk allows site users with high privileges to escalate to root by manipulating site co

CVE-2024-8606 CRITICAL
9.2 Sep 23

Bypass of two factor authentication in RestAPI in Checkmk < 2.3.0p16 and < 2.2.0p34 allows authenticated users to bypass

CVE-2023-31209 HIGH
8.8 Aug 10

Improper neutralization of active check command arguments in Checkmk < 2.1.0p32, < 2.0.0p38, < 2.2.0p4 leads to arbitrar

CVE-2023-31208 HIGH
8.8 May 17

Improper neutralization of livestatus command delimiters in the RestAPI in Checkmk < 2.0.0p36, < 2.1.0p28, and < 2.2.0b8

References

Advisories & patches

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy