The following security updates has been released for Ubuntu Linux:

USN-3850-2: NSS vulnerabilities
USN-3891-1: systemd vulnerability

USN-3850-2: NSS vulnerabilities

==========================================================================
Ubuntu Security Notice USN-3850-2
February 18, 2019

nss vulnerabilities
==========================================================================

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

- Ubuntu 12.04 ESM

Summary:

Several security issues were fixed in NSS.

Software Description:
- nss: Network Security Service library

Details:

USN-3850-1 fixed several vulnerabilities in NSS. This update provides
the corresponding update for Ubuntu 12.04 ESM.

Original advisory details:

 Keegan Ryan discovered that NSS incorrectly handled ECDSA key
 generation. A local attacker could possibly use this issue to perform
 a cache-timing attack and recover private ECDSA keys. (CVE-2018-0495)

 It was discovered that NSS incorrectly handled certain v2-compatible
 ClientHello messages. A remote attacker could possibly use this issue
 to perform a replay attack. (CVE-2018-12384)

 It was discovered that NSS incorrectly handled certain padding
 oracles. A remote attacker could possibly use this issue to perform a
 variant of the Bleichenbacher attack. (CVE-2018-12404)

Update instructions:

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

Ubuntu 12.04 ESM:
  libnss3 2:3.28.4-0ubuntu0.12.04.2

After a standard system update you need to restart any applications
that use NSS, such as Evolution, to make all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3850-2
  https://usn.ubuntu.com/usn/usn-3850-1
  CVE-2018-0495, CVE-2018-12384, CVE-2018-12404

USN-3891-1: systemd vulnerability

==========================================================================
Ubuntu Security Notice USN-3891-1
February 18, 2019

systemd vulnerability
==========================================================================

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

- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

systemd could be made to crash if it received specially a crafted
D-Bus message.

Software Description:
- systemd: system and service manager

Details:

It was discovered that systemd incorrectly handled certain D-Bus messages.
A local unprivileged attacker could exploit this in order to crash the
init process, resulting in a system denial-of-service (kernel panic).

Update instructions:

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

Ubuntu 18.10:
libsystemd0 239-7ubuntu10.8
systemd 239-7ubuntu10.8

Ubuntu 18.04 LTS:
libsystemd0 237-3ubuntu10.13
systemd 237-3ubuntu10.13

Ubuntu 16.04 LTS:
libsystemd0 229-4ubuntu21.16
systemd 229-4ubuntu21.16

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

References:
https://usn.ubuntu.com/usn/usn-3891-1
CVE-2019-6454

Package Information:
https://launchpad.net/ubuntu/+source/systemd/239-7ubuntu10.8
https://launchpad.net/ubuntu/+source/systemd/237-3ubuntu10.13
https://launchpad.net/ubuntu/+source/systemd/229-4ubuntu21.16