Debian: DSA-4694-1 Critical Unbound Update for Denial of Service

Two vulnerabiliites have been discovered in Unbound, a recursive-only
caching DNS server; a traffic amplification attack against third party
authoritative name servers (NXNSAttack) and insufficient sanitisation
of replies from upstream servers could result in denial of service via
an infinite loop.

The version of Unbound in the oldstable distribution (stretch) is
no longer supported. If these security issues affect your setup, you
should upgrade to the stable distribution (buster).

For the stable distribution (buster), these problems have been fixed in
version 1.9.0-2+deb10u2.

We recommend that you upgrade your unbound packages.

For the detailed security status of unbound please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/unbound

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/