=========================================================================Ubuntu Security Notice USN-4365-1
May 19, 2020

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

- Ubuntu 20.04 LTS
- Ubuntu 19.10
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Bind.

Software Description:
- bind9: Internet Domain Name Server

Details:

Lior Shafir, Yehuda Afek, and Anat Bremler-Barr discovered that Bind
incorrectly limited certain fetches. A remote attacker could possibly use
this issue to cause Bind to consume resources, leading to a denial of
service, or possibly use Bind to perform a reflection attack.
(CVE-2020-8616)

Tobias Klein discovered that Bind incorrectly handled checking TSIG
validity. A remote attacker could use this issue to cause Bind to crash,
resulting in a denial of service, or possibly perform other attacks.
(CVE-2020-8617)

Update instructions:

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

Ubuntu 20.04 LTS:
  bind9                           1:9.16.1-0ubuntu2.1

Ubuntu 19.10:
  bind9                           1:9.11.5.P4+dfsg-5.1ubuntu2.2

Ubuntu 18.04 LTS:
  bind9                           1:9.11.3+dfsg-1ubuntu1.12

Ubuntu 16.04 LTS:
  bind9                           1:9.10.3.dfsg.P4-8ubuntu1.16

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

References:
  https://ubuntu.com/security/notices/USN-4365-1
  CVE-2020-8616, CVE-2020-8617

Package Information:
  https://launchpad.net/ubuntu/+source/bind9/1:9.16.1-0ubuntu2.1
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.5.P4+dfsg-5.1ubuntu2.2
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.3+dfsg-1ubuntu1.12
  https://launchpad.net/ubuntu/+source/bind9/1:9.10.3.dfsg.P4-8ubuntu1.16