CVE-2021-40874

Name: CVE-2021-40874
Creator: NVD / NIST
Published: 2022-07-18T00:15:08.373+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.93%

Last modified Jun 17, 2026

CVE-2021-40874 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in LemonLDAP::NG (aka lemonldap-ng) 2.0.13. When using the RESTServer plug-in to operate a REST password validation service (for another LemonLDAP::NG instance, for example) and using the Kerberos authentication method combined with another method with the Combination authentication plug-in, any password will be recognized as valid for an existing user.. EPSS estimates a 0.93% chance of exploitation in the next 30 days.

Description

An issue was discovered in LemonLDAP::NG (aka lemonldap-ng) 2.0.13. When using the RESTServer plug-in to operate a REST password validation service (for another LemonLDAP::NG instance, for example) and using the Kerberos authentication method combined with another method with the Combination authentication plug-in, any password will be recognized as valid for an existing user.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.93%

55.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-287

Affected Software

Vendor	Product	Versions	Update
Lemonldap-Ng	Lemonldap\	\	Ng
Debian	Debian Linux	10.0	—

References

https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/issues/2612Exploit, Issue Tracking, Patch, Third Party Advisory
https://gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/issues/2612Exploit, Issue Tracking, Patch, Third Party Advisory

Timeline

Published: Jul 18, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-40874?

How severe is CVE-2021-40874?

CVE-2021-40874 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.93% probability of exploitation in the next 30 days.

How do I fix CVE-2021-40874?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-40874?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST