The following updates has been released for Ubuntu Linux:

USN-3816-3: systemd regression
USN-3827-2: Samba vulnerabilities
USN-3828-1: WebKitGTK+ vulnerabilities
USN-3829-1: Git vulnerabilities

USN-3816-3: systemd regression

==========================================================================
Ubuntu Security Notice USN-3816-3
November 27, 2018

systemd regression
==========================================================================

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

- Ubuntu 16.04 LTS

Summary:

USN-3816-1 caused a regression in systemd-tmpfiles.

Software Description:
- systemd: system and service manager

Details:

USN-3816-1 fixed vulnerabilities in systemd. The fix for CVE-2018-6954
caused a regression in systemd-tmpfiles when running Ubuntu inside a
container on some older kernels. This issue only affected Ubuntu 16.04
LTS. In order to continue to support this configuration, the fixes for
CVE-2018-6954 have been reverted.

We apologize for the inconvenience.

Original advisory details:

 Jann Horn discovered that unit_deserialize incorrectly handled status
messages
 above a certain length. A local attacker could potentially exploit this via
 NotifyAccess to inject arbitrary state across re-execution and obtain root
 privileges. (CVE-2018-15686)
 
 Jann Horn discovered a race condition in chown_one(). A local attacker
 could potentially exploit this by setting arbitrary permissions on certain
 files to obtain root privileges. This issue only affected Ubuntu 18.04 LTS
 and Ubuntu 18.10. (CVE-2018-15687)
 
 It was discovered that systemd-tmpfiles mishandled symlinks in
 non-terminal path components. A local attacker could potentially exploit
 this by gaining ownership of certain files to obtain root privileges. This
 issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2018-6954)

Update instructions:

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

Ubuntu 16.04 LTS:
  systemd  229-4ubuntu21.10

After a standard system update you need to reboot your computer to make
all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3816-3
  https://usn.ubuntu.com/usn/usn-3816-1
  https://launchpad.net/bugs/1804847

Package Information:
  https://launchpad.net/ubuntu/+source/systemd/229-4ubuntu21.10

USN-3827-2: Samba vulnerabilities

==========================================================================
Ubuntu Security Notice USN-3827-2
November 27, 2018

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

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

- Ubuntu 12.04 ESM

Summary:

Several security issues were fixed in Samba.

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

Details:

USN-3827-1 fixed a vulnerability in samba. This update provides
the corresponding update for Ubuntu 12.04 ESM.


Original advisory details:

 Florian Stuelpner discovered that Samba incorrectly handled CNAME
 records. A remote attacker could use this issue to cause Samba to
 crash, resulting in a denial of service. (CVE-2018-14629)

 Alex MacCuish discovered that Samba incorrectly handled memory when
 configured to accept smart-card authentication. A remote attacker
 could possibly use this issue to cause Samba to crash, resulting in a
 denial of service. (CVE-2018-16841)

 Garming Sam discovered that Samba incorrectly handled memory when
 processing LDAP searches. A remote attacker could possibly use this
 issue to cause Samba to crash, resulting in a denial of service. 
 (CVE-2018-16851)

Update instructions:

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

Ubuntu 12.04 ESM:
  samba 2:3.6.25-0ubuntu0.12.04.16

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

References:
  https://usn.ubuntu.com/usn/usn-3827-2
  https://usn.ubuntu.com/usn/usn-3827-1
  CVE-2018-14629, CVE-2018-16841, CVE-2018-16851

USN-3828-1: WebKitGTK+ vulnerabilities

==========================================================================
Ubuntu Security Notice USN-3828-1
November 27, 2018

webkit2gtk vulnerabilities
==========================================================================

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

- Ubuntu 18.10
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in WebKitGTK+.

Software Description:
- webkit2gtk: Web content engine library for GTK+

Details:

A large number of security issues were discovered in the WebKitGTK+ Web and
JavaScript engines. If a user were tricked into viewing a malicious
website, a remote attacker could exploit a variety of issues related to web
browser security, including cross-site scripting attacks, denial of service
attacks, and arbitrary code execution.

Update instructions:

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

Ubuntu 18.10:
libjavascriptcoregtk-4.0-18 2.22.4-0ubuntu0.18.10.1
libwebkit2gtk-4.0-37 2.22.4-0ubuntu0.18.10.1

Ubuntu 18.04 LTS:
libjavascriptcoregtk-4.0-18 2.22.4-0ubuntu0.18.04.1
libwebkit2gtk-4.0-37 2.22.4-0ubuntu0.18.04.1

This update uses a new upstream release, which includes additional bug
fixes. After a standard system update you need to restart any applications
that use WebKitGTK+, such as Epiphany, to make all the necessary changes.

References:
https://usn.ubuntu.com/usn/usn-3828-1
CVE-2018-4345, CVE-2018-4372, CVE-2018-4386

Package Information:
https://launchpad.net/ubuntu/+source/webkit2gtk/2.22.4-0ubuntu0.18.10.1
https://launchpad.net/ubuntu/+source/webkit2gtk/2.22.4-0ubuntu0.18.04.1

USN-3829-1: Git vulnerabilities

==========================================================================
Ubuntu Security Notice USN-3829-1
November 27, 2018

git vulnerabilities
==========================================================================

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

- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in Git.

Software Description:
- git: fast, scalable, distributed revision control system

Details:

It was discovered that Git incorrectly handled layers of tree objects.
An attacker could possibly use this issue to cause a denial of service.
This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS.
(CVE-2017-15298)

It was discovered that Git incorrectly handled certain inputs.
An attacker could possibly use this issue to execute arbitrary code.
This issue only affected Ubuntu 18.04 LTS and Ubuntu 18.10.
(CVE-2018-19486)

Update instructions:

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

Ubuntu 18.10:
  git 1:2.19.1-1ubuntu1.1

Ubuntu 18.04 LTS:
  git 1:2.17.1-1ubuntu0.4

Ubuntu 16.04 LTS:
  git 1:2.7.4-0ubuntu1.6

Ubuntu 14.04 LTS:
  git 1:1.9.1-1ubuntu0.10

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

References:
  https://usn.ubuntu.com/usn/usn-3829-1
  CVE-2017-15298, CVE-2018-19486

Package Information:
  https://launchpad.net/ubuntu/+source/git/1:2.19.1-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/git/1:2.17.1-1ubuntu0.4
  https://launchpad.net/ubuntu/+source/git/1:2.7.4-0ubuntu1.6
  https://launchpad.net/ubuntu/+source/git/1:1.9.1-1ubuntu0.10