It has recently been published the description of Zerologon, CVE-2020-1472 (see here for a summary and here for the technical paper), and do not worry since the bug has already been patched by Microsoft in August (see here). 

The bug allows anyone who can connect in TCP/RPC/Netlogon to an unpatched Active Directory domain controller to become a domain administrator, nothing else needed. The cause of this bug is a minor glitch in the implementation of the cryptographic algorithm AES-CFB8: the Initialisation Vector has been kept fixed at zero instead to be unique and randomly generated (more details are provided in the technical paper mentioned above).