Ubuntu Security Notice 3092-1 – Stefan Metzmacher discovered that Samba incorrectly handled certain flags in SMB2/3 client connections. A remote attacker could use this issue to disable client signing and impersonate servers by performing a man in the middle attack. Samba has been updated to 4.3.11 in Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. In addition to the security fix, the updated packages contain bug fixes, new features, and possibly incompatible changes. Various other issues were also addressed.