=========================================================================Ubuntu Security Notice USN-5332-1
March 17, 2022

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

- Ubuntu 21.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Bind.

Software Description:
- bind9: Internet Domain Name Server

Details:

Xiang Li, Baojun Liu, Chaoyi Lu, and Changgen Zou discovered that Bind
incorrectly handled certain bogus NS records when using forwarders. A
remote attacker could possibly use this issue to manipulate cache results.
(CVE-2021-25220)

It was discovered that Bind incorrectly handled certain crafted TCP
streams. A remote attacker could possibly use this issue to cause Bind to
consume resources, leading to a denial of service. This issue only affected
Ubuntu 21.10. (CVE-2022-0396)

Update instructions:

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

Ubuntu 21.10:
  bind9                           1:9.16.15-1ubuntu1.2

Ubuntu 20.04 LTS:
  bind9                           1:9.16.1-0ubuntu2.10

Ubuntu 18.04 LTS:
  bind9                           1:9.11.3+dfsg-1ubuntu1.17

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

References:
  https://ubuntu.com/security/notices/USN-5332-1
  CVE-2021-25220, CVE-2022-0396

Package Information:
  https://launchpad.net/ubuntu/+source/bind9/1:9.16.15-1ubuntu1.2
  https://launchpad.net/ubuntu/+source/bind9/1:9.16.1-0ubuntu2.10
  https://launchpad.net/ubuntu/+source/bind9/1:9.11.3+dfsg-1ubuntu1.17