The following updates has been released for Ubuntu Linux:

USN-3968-2: Sudo vulnerability
USN-3996-1: GNU Screen vulnerability

USN-3968-2: Sudo vulnerability

==========================================================================
Ubuntu Security Notice USN-3968-2
May 29, 2019

sudo vulnerability
==========================================================================

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

- Ubuntu 14.04 ESM

Summary:

Sudo could be made to overwrite files if it received a specially
crafted input.

Software Description:
- sudo: Provide limited super user privileges to specific users

Details:

USN-3968-1 fixed a vulnerability in Sudo. This update provides
the corresponding update for Ubuntu 14.04 ESM.

Original advisory details:

 It was discovered that Sudo did not properly parse the contents of
 /proc/[pid]/stat when attempting to determine its controlling tty. A
 local attacker in some configurations could possibly use this to
 overwrite any file on the filesystem, bypassing intended permissions.
 (CVE-2017-1000368)

Update instructions:

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

Ubuntu 14.04 ESM:
  sudo 1.8.9p5-1ubuntu1.5+esm1
  sudo-ldap 1.8.9p5-1ubuntu1.5+esm1

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

References:
  https://usn.ubuntu.com/usn/usn-3968-2
  https://usn.ubuntu.com/usn/usn-3968-1
  CVE-2017-1000368

USN-3996-1: GNU Screen vulnerability

==========================================================================
Ubuntu Security Notice USN-3996-1
May 29, 2019

GNU Screen vulnerability
==========================================================================

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

- Ubuntu 14.04 ESM
- Ubuntu 12.04 ESM

Summary:

GNU Screen could be made to crash or run programs as your login if it
opened a specially crafted file or received specially crafted input.

Software Description:
- screen: terminal multiplexer with VT100/ANSI terminal emulation

Details:

Kuang-che Wu discovered that GNU Screen improperly handled certain input. An
attacker could use this issue to cause GNU Screen to crash, resulting in a
denial of service or the execution of arbitrary code.

Update instructions:

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

Ubuntu 14.04 ESM:
screen 4.1.0~20120320gitdb59704-9ubuntu0.1~esm1

Ubuntu 12.04 ESM:
screen 4.0.3-14ubuntu8.1

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

References:
https://usn.ubuntu.com/usn/usn-3996-1
CVE-2015-6806