The samba project reports:
All versions of Samba from 4.0.0 onwards are vulnerable to infinite
query recursion caused by CNAME loops. Any dns record can be added via
ldap by an unprivileged user using the ldbadd tool, so this is a
security issue.
When configured to accept smart-card authentication, Samba's KDC will call
talloc_free() twice on the same memory if the principal in a validly signed
certificate does not match the principal in the AS-REQ.
During the processing of an LDAP search before Samba's AD DC returns
the LDAP entries to the client, the entries are cached in a single
memory object with a maximum size of 256MB. When this size is
reached, the Samba process providing the LDAP service will follow the
NULL pointer, terminating the process.
During the processing of an DNS zone in the DNS management DCE/RPC server,
the internal DNS server or the Samba DLZ plugin for BIND9, if the
DSPROPERTY_ZONE_MASTER_SERVERS property or DSPROPERTY_ZONE_SCAVENGING_SERVERS
property is set, the server will follow a NULL pointer and terminate
A user in a Samba AD domain can crash the KDC when Samba is built in the
non-default MIT Kerberos configuration.
AD DC Configurations watching for bad passwords (to restrict brute forcing
of passwords) in a window of more than 3 minutes may not watch for bad
passwords at all.