USN-3426-1 fixed several vulnerabilities in Samba. This update
provides the corresponding update for Ubuntu 12.04 ESM.
Original advisory details:
Stefan Metzmacher discovered that Samba incorrectly enforced SMB signing in
certain situations. A remote attacker could use this issue to perform a
machine-in-the-middle attack. (CVE-2017-12150)
Yihan Lian and Zhibin Hu discovered that Samba incorrectly handled memory
when SMB1 is being used. A remote attacker could possibly use this issue to
obtain server memory contents. (CVE-2017-12163)