=========================================================================
Ubuntu Security Notice USN-4454-2
August 10, 2020

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

- Ubuntu 14.04 ESM
- Ubuntu 12.04 ESM

Summary:

Samba could be made to crash if it received specially crafted network
traffic.

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

Details:

USN-4454-1 fixed a vulnerability in Samba. This update provides
the corresponding update for Ubuntu 12.04 ESM and Ubuntu 14.04 ESM.

Original advisory details:

 Martin von Wittich and Wilko Meyer discovered that Samba incorrectly
 handled certain empty UDP packets when being used as a AD DC NBT server. A
 remote attacker could possibly use this issue to cause Samba to crash,
 resulting in a denial of service.

Update instructions:

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

Ubuntu 14.04 ESM:
  samba                           2:4.3.11+dfsg-0ubuntu0.14.04.20+esm8

Ubuntu 12.04 ESM:
  samba                           2:3.6.25-0ubuntu0.12.04.21

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

References:
  https://usn.ubuntu.com/4454-2
  https://usn.ubuntu.com/4454-1
  CVE-2020-14303