A couple of bugs in some Samba software can help an attacker crash key processes on the network in charge of providing directory, application, and other services. The two vulnerabilities can be leveraged separately to crash the LDAP (Lightweight Directory Access Protocol) and the RPC (remote procedural call) server processes in Samba Active Directory Domain Controller. One of the issues is tracked as CVE-2019-12436 and affects all Samba versions since 4.0 but the current one, 4.10.5, which includes a fix.
Source: https://www.bleepingcomputer.com/news/security/samba-vulnerability-can-crash-active-directory-components/