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Ubuntu Security Notice USN-3426-1
September 21, 2017

samba vulnerabilities
==========================================================================

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

- Ubuntu 17.04
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Samba could be made to expose sensitive information over the network.

Software Description:
- samba: SMB/CIFS file, print, and login server for Unix

Details:

Stefan Metzmacher discovered that Samba incorrectly enforced SMB signing in
certain situations. A remote attacker could use this issue to perform a man
in the middle attack. (CVE-2017-12150)

Stefan Metzmacher discovered that Samba incorrectly handled encryption
across DFS redirects. A remote attacker could use this issue to perform a
man in the middle attack. (CVE-2017-12151)

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)

Update instructions:

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

Ubuntu 17.04:
  samba                           2:4.5.8+dfsg-0ubuntu0.17.04.7

Ubuntu 16.04 LTS:
  samba                           2:4.3.11+dfsg-0ubuntu0.16.04.11

Ubuntu 14.04 LTS:
  samba                           2:4.3.11+dfsg-0ubuntu0.14.04.12

In general, a standard system update will make all the necessary changes.

References:
  https://www.ubuntu.com/usn/usn-3426-1
  CVE-2017-12150, CVE-2017-12151, CVE-2017-12163

Package Information:
  https://launchpad.net/ubuntu/+source/samba/2:4.5.8+dfsg-0ubuntu0.17.04.7
  https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.16.04.11
  https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.14.04.12