1. Ubuntu Security Notices
  2. USN-3673-1

USN-3673-1: Unbound vulnerability

Publication date

7 June 2018

Overview

A security issue was fixed in Unbound.

Releases

Packages

  • 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.

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

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
18.04 bionic libunbound2 –  1.6.7-1ubuntu2.1
unbound –  1.6.7-1ubuntu2.1
17.10 artful libunbound2 –  1.6.5-1ubuntu0.2
unbound –  1.6.5-1ubuntu0.2
16.04 xenial libunbound2 –  1.5.8-1ubuntu1.1
unbound –  1.5.8-1ubuntu1.1
14.04 trusty libunbound2 –  1.4.22-1ubuntu4.14.04.3
unbound –  1.4.22-1ubuntu4.14.04.3

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Get Ubuntu Pro

References

Have additional questions?

Talk to a member of the team ›