USN-3092-1: Samba vulnerability

28 September 2016

samba vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS


Samba could be tricked into connecting to impersonated servers.

Software Description

  • samba - SMB/CIFS file, print, and login server for Unix


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.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 16.04 LTS
samba - 2:4.3.11+dfsg-0ubuntu0.16.04.1
Ubuntu 14.04 LTS
samba - 2:4.3.11+dfsg-0ubuntu0.14.04.1

To update your system, please follow these instructions:

This update uses a new upstream release, which includes additional bug fixes. In general, a standard system update will make all the necessary changes.