CVE-2021-40906

Summary

CVECVE-2021-40906
StatePUBLISHED
Assignermitre
Source PriorityCVE Program / NVD first with legacy fallback
Published2022-03-25 23:15:08 UTC
Updated2026-07-09 01:17:02 UTC
DescriptionCheckMK Raw Edition software (versions 1.5.0 to 1.6.0) does not sanitise the input of a web service parameter that is in an unauthenticated zone. This Reflected XSS allows an attacker to open a backdoor on the device with HTML content and interpreted by the browser (such as JavaScript or other client-side scripts) or to steal the session cookies of a user who has previously authenticated via a man in the middle. Successful exploitation requires access to the web service resource without authentication.

Risk And Classification

Primary CVSS: v3.1 6.1 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS: 0.009740000 probability, percentile 0.579210000 (date 2026-07-12)

Problem Types: CWE-79 | n/a


VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary6.1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
2.0[email protected]Primary4.3AV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS v3.1 Breakdown

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None

AV:N/AC:M/Au:N/C:N/I:P/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Checkmk Checkmk All All All All
Application Checkmk Checkmk 1.6.0 - All All
Application Checkmk Checkmk 1.6.0 b1 All All
Application Checkmk Checkmk 1.6.0 b10 All All
Application Checkmk Checkmk 1.6.0 b12 All All
Application Checkmk Checkmk 1.6.0 b3 All All
Application Checkmk Checkmk 1.6.0 b4 All All
Application Checkmk Checkmk 1.6.0 b5 All All
Application Checkmk Checkmk 1.6.0 b9 All All
Application Checkmk Checkmk 1.6.0 p1 All All
Application Checkmk Checkmk 1.6.0 p10 All All
Application Checkmk Checkmk 1.6.0 p11 All All
Application Checkmk Checkmk 1.6.0 p12 All All
Application Checkmk Checkmk 1.6.0 p13 All All
Application Checkmk Checkmk 1.6.0 p14 All All
Application Checkmk Checkmk 1.6.0 p15 All All
Application Checkmk Checkmk 1.6.0 p16 All All
Application Checkmk Checkmk 1.6.0 p19 All All
Application Checkmk Checkmk 1.6.0 p2 All All
Application Checkmk Checkmk 1.6.0 p20 All All
Application Checkmk Checkmk 1.6.0 p21 All All
Application Checkmk Checkmk 1.6.0 p22 All All
Application Checkmk Checkmk 1.6.0 p23 All All
Application Checkmk Checkmk 1.6.0 p24 All All
Application Checkmk Checkmk 1.6.0 p25 All All
Application Checkmk Checkmk 1.6.0 p3 All All
Application Checkmk Checkmk 1.6.0 p4 All All
Application Checkmk Checkmk 1.6.0 p5 All All
Application Checkmk Checkmk 1.6.0 p6 All All
Application Checkmk Checkmk 1.6.0 p7 All All
Application Checkmk Checkmk 1.6.0 p8 All All
Application Checkmk Checkmk 1.6.0 p9 All All
Application Tribe29 Checkmk 1.6.0b10 All All All
Application Tribe29 Checkmk 1.6.0b11 All All All
Application Tribe29 Checkmk 1.6.0p10 All All All
Application Tribe29 Checkmk 1.6.0p17 All All All
Application Tribe29 Checkmk 1.6.0p18 All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Na N/a affected n/a Not specified

References

ReferenceSourceLinkTags
GitHub - Edgarloyola/CVE-2021-40906 af854a3a-2127-422b-91ae-364da2661108 github.com Third Party Advisory
Infrastructure & Application Monitoring with Checkmk MITRE checkmk.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 198866 Ubuntu Security Notification for Checkmk Vulnerabilities (USN-5527-1)

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