=========================================================================Ubuntu Security Notice USN-3976-3
May 27, 2019

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

USN-3976-1 introduced a regression in Samba.

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

Details:

USN-3976-1 fixed a vulnerability in Samba. The update introduced a
regression causing Samba to occasionally crash. This update fixes the
problem.

We apologize for the inconvenience.

Original advisory details:

 Isaac Boukris and Andrew Bartlett discovered that Samba incorrectly checked
 S4U2Self packets. In certain environments, a remote attacker could possibly
 use this issue to escalate privileges.

Update instructions:

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

Ubuntu 18.04 LTS:
  samba                           2:4.7.6+dfsg~ubuntu-0ubuntu2.11

Ubuntu 16.04 LTS:
  samba                           2:4.3.11+dfsg-0ubuntu0.16.04.21

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

References:
  https://ubuntu.com/security/notices/USN-3976-3
  https://ubuntu.com/security/notices/USN-3976-1
  https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1827924

Package Information:
  https://launchpad.net/ubuntu/+source/samba/2:4.7.6+dfsg~ubuntu-0ubuntu2.11
  https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.16.04.21