=========================================================================Ubuntu Security Notice USN-3956-1
April 25, 2019

bind9 vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 19.04
- Ubuntu 18.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Bind could be made to consume resources if it received specially crafted
network traffic.

Software Description:
- bind9: Internet Domain Name Server

Details:

It was discovered that Bind incorrectly handled limiting the number of
simultaneous TCP clients. A remote attacker could possibly use this issue
to cause Bind to consume resources, leading to a denial of service.

Update instructions:

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

Ubuntu 19.04:
  bind9                           1:9.11.5.P1+dfsg-1ubuntu2.3

Ubuntu 18.10:
  bind9                           1:9.11.4+dfsg-3ubuntu5.3

Ubuntu 18.04 LTS:
  bind9                           1:9.11.3+dfsg-1ubuntu1.7

Ubuntu 16.04 LTS:
  bind9                           1:9.10.3.dfsg.P4-8ubuntu1.14

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

References:
  https://ubuntu.com/security/notices/USN-3956-1
  CVE-2018-5743

Package Information:
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.5.P1+dfsg-1ubuntu2.3
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.4+dfsg-3ubuntu5.3
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.3+dfsg-1ubuntu1.7
  https://launchpad.net/ubuntu/+source/bind9/1:9.10.3.dfsg.P4-8ubuntu1.14