CVE-2021-40874 Auth bypass in n/a

What is CVE-2021-40874?

CVE-2021-40874 is a critical authentication bypass vulnerability in Debian Debian Linux, published on 17 Jul 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

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.

Weakness: CWE-287

Which versions are affected by CVE-2021-40874?

It affects 2 products.

Products include Debian Debian Linux, Lemonldap-Ng Lemonldap\.

How do I fix CVE-2021-40874?

Upgrade to a fixed version.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2021-40874 being exploited?

There is no known exploitation of CVE-2021-40874 in the wild and no public exploit code.

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• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-40874, GHSA-gvrq-49rv-2rq7, UBUNTU-CVE-2021-40874.