unbound vulnerability

7 June 2018

unbound vulnerability

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

• Ubuntu 18.04 LTS
• Ubuntu 17.10
• Ubuntu 16.04 LTS
• Ubuntu 14.04 LTS

Summary

A security issue was fixed in Unbound.

Software Description

• unbound - validating, recursive, caching DNS resolver

Details

Ralph Dolmans and Karst Koymans discovered that Unbound did not properly handle certain NSEC records. An attacker could use this to to prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick Unbound into accepting a NODATA proof.

Update instructions

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

Ubuntu 18.04 LTS

libunbound2 - 1.6.7-1ubuntu2.1

unbound - 1.6.7-1ubuntu2.1

Ubuntu 17.10

libunbound2 - 1.6.5-1ubuntu0.2

unbound - 1.6.5-1ubuntu0.2

Ubuntu 16.04 LTS

libunbound2 - 1.5.8-1ubuntu1.1

unbound - 1.5.8-1ubuntu1.1

Ubuntu 14.04 LTS

libunbound2 - 1.4.22-1ubuntu4.14.04.3

unbound - 1.4.22-1ubuntu4.14.04.3

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References

• CVE-2017-15105