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Ubuntu Security Notice USN-4244-1
January 21, 2020

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

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

- Ubuntu 19.10
- Ubuntu 19.04
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Samba.

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

Details:

It was discovered that Samba did not automatically replicate ACLs set to
inherit down a subtree on AD Directory, contrary to expectations. This
issue was only addressed in Ubuntu 18.04 LTS, Ubuntu 19.04 and Ubuntu
19.10. (CVE-2019-14902)

Robert Święcki discovered that Samba incorrectly handled certain character
conversions when the log level is set to 3 or above. In certain
environments, a remote attacker could possibly use this issue to cause
Samba to crash, resulting in a denial of service. (CVE-2019-14907)

Christian Naumer discovered that Samba incorrectly handled DNS zone
scavenging. This issue could possibly result in some incorrect data being
written to the DB. This issue only applied to Ubuntu 19.04 and Ubuntu
19.10. (CVE-2019-19344)

Update instructions:

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

Ubuntu 19.10:
  samba                           2:4.10.7+dfsg-0ubuntu2.4

Ubuntu 19.04:
  samba                           2:4.10.0+dfsg-0ubuntu2.8

Ubuntu 18.04 LTS:
  samba                           2:4.7.6+dfsg~ubuntu-0ubuntu2.15

Ubuntu 16.04 LTS:
  samba                           2:4.3.11+dfsg-0ubuntu0.16.04.25

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

References:
  https://usn.ubuntu.com/4244-1
  CVE-2019-14902, CVE-2019-14907, CVE-2019-19344

Package Information:
  https://launchpad.net/ubuntu/+source/samba/2:4.10.7+dfsg-0ubuntu2.4
  https://launchpad.net/ubuntu/+source/samba/2:4.10.0+dfsg-0ubuntu2.8
  https://launchpad.net/ubuntu/+source/samba/2:4.7.6+dfsg~ubuntu-0ubuntu2.15
  https://launchpad.net/ubuntu/+source/samba/2:4.3.11+dfsg-0ubuntu0.16.04.25