Jenkins Active Directory Plugin 2.19 and earlier does not prohibit the use of an empty password in Windows/ADSI mode, which allows attackers to log in to Jenkins as any user depending on the configuration of the Active Directory server.
https://github.com/advisories/GHSA-8wcw-cw2f-h4g2
https://www.jenkins.io/security/advisory/2020-11-04/#SECURITY-2099