Jenkins Active Directory Plugin 2.41.1 and earlier does not escape the user name before building the LDAP search filter in the Windows native (ADSI) authentication path, allowing unauthenticated attackers to inject LDAP wildcard characters to enumerate directory entries and to authenticate as a matching user whose password they know without knowing their exact user name.
Jenkins Active Directory Plugin 2.30 and earlier ignores the "Require TLS" and "StartTls" options and always performs the connection test to Active directory unencrypted, allowing attackers able to capture network traffic between the Jenkins controller and Active Directory servers to obtain Active Directory credentials.