=========================================================================Ubuntu Security Notice USN-5732-1
November 17, 2022

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

- Ubuntu 22.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Unbound could be made to stop responding if it received specially crafted
network traffic.

Software Description:
- unbound: validating, recursive, caching DNS resolver

Details:

It was discovered that Unbound incorrectly handled delegations with a large
number of non-responsive nameservers. A remote attacker could possibly use
this issue to cause Unbound 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 22.10:
   libunbound8                     1.16.2-1ubuntu0.1
   unbound                         1.16.2-1ubuntu0.1

Ubuntu 22.04 LTS:
   libunbound8                     1.13.1-1ubuntu5.3
   unbound                         1.13.1-1ubuntu5.3

Ubuntu 20.04 LTS:
   libunbound8                     1.9.4-2ubuntu1.4
   unbound                         1.9.4-2ubuntu1.4

Ubuntu 18.04 LTS:
   libunbound2                     1.6.7-1ubuntu2.6
   unbound                         1.6.7-1ubuntu2.6

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

References:
   https://ubuntu.com/security/notices/USN-5732-1
   CVE-2022-3204

Package Information:
   https://launchpad.net/ubuntu/+source/unbound/1.16.2-1ubuntu0.1
   https://launchpad.net/ubuntu/+source/unbound/1.13.1-1ubuntu5.3
   https://launchpad.net/ubuntu/+source/unbound/1.9.4-2ubuntu1.4
   https://launchpad.net/ubuntu/+source/unbound/1.6.7-1ubuntu2.6