Is CVE-2021-40874 actively exploited?

No active exploitation of CVE-2021-40874 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-40874 be exploited remotely?

Yes. CVE-2021-40874 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-40874?

CVE-2021-40874 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-40874

CRITICAL

CVE-2021-40874

CWE-287Published: July 18, 2022· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-40874 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.