According to the United States Computer Emergency Readiness Team, Linux and Unix based operating systems employing Samba versions 3.5.0 through 4.2.0rc4 contain a vulnerability in the Server Message Block daemon (smbd). Exploitation of this vulnerability may allow a remote attacker to take control of an affected system.
US-CERT recommends users and administrators refer to their respective Linux OS vendor(s) for an appropriate patch if affected. Patches are currently available from Debian, Red Hat, Suse, and Ubuntu. A Samba patch is available for experienced users and administrators to implement.0