An Unbound security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, and 22.04 LTS.

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Ubuntu Security Notice USN-5569-1
August 16, 2022

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

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

Summary:

Unbound could be made to cache rogue domain names.

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

Details:

Xiang Li discovered that Unbound incorrectly handled delegation caching.
A remote attacker could use this issue to keep rogue domain names
resolvable long after they have been revoked.

Update instructions:

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

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

Ubuntu 20.04 LTS:
libunbound8 1.9.4-2ubuntu1.3
unbound 1.9.4-2ubuntu1.3

Ubuntu 18.04 LTS:
libunbound2 1.6.7-1ubuntu2.5
unbound 1.6.7-1ubuntu2.5

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

References:
  https://ubuntu.com/security/notices/USN-5569-1
CVE-2022-30698, CVE-2022-30699

Package Information:
  https://launchpad.net/ubuntu/+source/unbound/1.13.1-1ubuntu5.1
  https://launchpad.net/ubuntu/+source/unbound/1.9.4-2ubuntu1.3
  https://launchpad.net/ubuntu/+source/unbound/1.6.7-1ubuntu2.5