Critical Unbound DNS Issue USN-3673-1 for Ubuntu 18.04 LTS Release

ubuntu

June 7, 2018

A security issue was fixed in Unbound.

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.

Topics Covered

security advisory critical update instructions ubuntu dns issue security notice unbound

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

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